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THE BUILDING AND ORNAMENTAL STONES 
OF NORTH CAROLINA 

BY 
THOMAS L. WATSON and FRANCIS B. LANEY 

WITH THE COLLABORATION OF 

GEORGE P. MERRILL 



{North Carolina State Library 'V 

Raleigh ° c v 



NORTH CAROLINA GEOLOGICAL SURVEY 

JOSEPH HYDE PRATT, STATE GEOLOGIST 



BULLETIN NO. 2 



THE BUILDING AND ORNAMENTAL 
STONES OF NORTH CAROLINA 



BY 

THOMAS L. WATSON and FRANCIS B. LANEY 

WITH THE COLLABOEATION OF 

GEORGE P. MERRILL 




RALEIGH 

E. M. Uzzell, Public Printer 

1906 



GEOLOGICAL BOARD 



Governor E. B. Glenn", ex officio Chairman Ealeigh. 

Henry E. Fries Winston-Salem. 

Frank E. Hewitt Asheville. 

Hugh McEae Wilmington. 

Frank Wood Edenton. 



STATE GEOLOGIST 
Joseph Hyde Pratt Chapel Hill. 



LETTER OF TRANSMITTAL 



Chapel Hill, N. C, April 1, 1906. 

To His Excellency, Hon. E. B. Glenn, 

Governor of North Carolina. 
Sir — I have the honor to submit for publication as Bulletin 2 of the 
Eeports of the North Carolina Geological Survey, a description of the 
Building and Ornamental Stones of North Carolina, which has been 
prepared by Prof essor Thomas L. Watson, of the Virginia Polytechnique 
Institute, Blacksburg, Va., and Mr. Francis B. Laney, of the Survey, 
with the collaboration of Mr. Geo. P. Merrill, Curator of the National 
Museum, Washington, D. C. 

This bulletin is intended to call attention to the economic value of the 
stone deposits in the State that are suitable for building and ornamental 
purposes. North Carolina is well supplied with stone that is adapted to 
all kinds of building purposes, and its geographic position renders it 
easily accessible to the markets of our largest cities for building stone. 

With great respect, 

Yours obediently, 

Joseph Hyde Peatt, 

State Geologist. 



CONTENTS 



PAGE 

Illustrations xiv 

Preface xvii 

Chapter I. — Preliminary generalities 1 

Essential qualities of building stone 1 

Surface features of the State 3 

Geographic position of the State considered with reference to other 

than local markets 4 

Chapter II. — The varieties of building stones 9 

The granites, gneisses, and associated crystalline siliceous rocks. 9 
Geographic distribution of the granites, gneisses, and associated 

crystalline siliceous rocks 11 

The granites of the Coastal Plain region 14 

General geographic and geologic description 14 

General field relations of the crystalline rocks 14 

Anson and Richmond counties 15 

The Wadesboro-Rockingham granite area 15 

Dikes of basic intrusive rocks in the Wadesboro-Rockingham 

crystalline area 20 

Wilson County 21 

The Contentnea Creek granite area 21 

The Elm City granite area 23 

Edgecombe and Nash counties 25 

Resume" of the granites of the coastal plain region 27 

The granites of the Piedmont Plateau region 28 

General geographic and geologic description 28 

The northeastern Carolina granite belt 29 

General considerations 29 

Wake County 30 

The Raleigh granite area 30 

The City quarries 30 

The Penitentiary quarry 34 

The Lewis place 35 

The Wyatt-Rolesville granite area 36 

Wyatt Station 36 

Rolesville 36 

Redford farm 36 



Vlll CONTENTS. 



PAGE 



Franklin County 38 

The Louisburg granite area 38 

Porphyritic granite 41 

Dikes of basic igneous rocks 41 

Warren County 42 

The Warrenton area 42 

The Warren Plains area ■ 43 

Vance County 44 

The Greystone granite area 45 

The Old Greystone quarry 46 

The New Greystone quarry 47 

The Greystone Granite and Construction Company's 

quarry 48 

The Seaboard Air Line Railway quarry 49 

The Middleburg quarries 50 

The Henderson granite area 52 

Granville County 53 

Resume of the northeastern Carolina granite belt 53 

The Carolina metamorphic slate and volcanic belt 54 

General description of the belt 54 

Orange County 55 

The Hillsboro area 56 

The Chapel Hill area 56 

The Carolina igneous belt (the main granite belt) 57 

General description of the belt 57 

General geologic relations 58 

Age relations of the rocks 59 

Description of the individual granite areas 61 

Gaston County 61 

The Gastonia granite area 62 

The Bell-Peysour openings 64 

The Jenkins quarry 65 

The Hope quarry 65 

Dikes of basic igneous rocks 66 

Mecklenburg County 67 

The Charlotte granite area 67 

The City quarry 67 

The Orders quarry 68 

The Snell opening 68 

The Dunn quarry 69 

The Smith quarry 69 

The Kirkpatrick opening 70 

The Caldwell place 70 

Quartz-poryphyry (leopardite) 70 

Location and description 71 

The Morning Glade Church area 74 

The Cross place 75 



CONTENTS. IX 

PAGE 

The Davidson Granite area 75 

The Caldwell place 76 

The Harriet Sloan Mill place 77 

The Knox quarry 78 

The Blakely quarry 78 

Dikes of basic intrusive rocks 79 

Iredell County 80 

The Mooresville granite area 81 

The even-grained granite 81 

The McNeely quarry 81 

The Breed quarry 82 

The Biddell quarry 84 

The Cotton Mill outcrop 86 

The porphyritic granite 86 

The Mount Mourne exposure 87 

Relations of the granites in the Mooresville area 88 

The Barium Springs granite area 89 

The Murdock place 90 

The Wilhelm place 90 

The Mills place 90 

Basic igneous intrusive rocks 91 

Cabarrus County 91 

The Rocky River granite area 92 

The Teeders place 92 

The Stewart place 92 

The southwest limits of Concord 93 

Augite-syenite 93 

Porphyritic granite 95 

Granite on the east side of Concord 96 

The Reid or City quarry 96 

Granite porphyry . 97 

Section along the road from near Mt. Pleasant to Concord 98 

Basic igneous rocks 99 

Rowan County 100 

The Dunns Mountain granite area 101 

Quarries on the north slope of Dunns Mountain 104 

The Dunns Mountain (McCanless) granite quarries 106 

The Rowan Granite Company's quarries 108 

The Balfour Quarry Company's quarries 110 

The Consolidated Granite Company's quarries Ill 

The Phillips Mountain quarries 113 

The Powlers Mountain quarries 114 

The Josey-Roger property 116 

The Woodleaf granite area 117 

The Salisbury porphyritic granite area 118 

Basic igneous rocks 119 

Diorite 119 



CONTENTS. 



PAGE 



Gabbro 120 

The McGalliard quarry 120 

Diabase 122 

Davidson County 122 

The Lexington granite area 123 

The Conrad place 123 

The Fritts place 124 

The Sink place 125 

Porphyritic granite 125 

Dikes of basic igneous rocks 126 

Davie County 127 

The Yadkin River granite area 127 

The even-grained granite 127 

The Hairston place 127 

The Cooleemee Cotton Mills 127 

Porphyritic granite 128 

Orbicular gabbro-diorite 129 

Basic igneous intrusive rocks 133 

Forsyth County 133 

The Winston granite area 133 

Porphyritic granite 133 

Gneiss 135 

Diabase dikes 135 

Guilford County 136 

The Brown-Summit granite area 136 

The Summerfield granite area 138 

The Hoskins place 138 

The Gamble place 139 

The Friendship granite area 140 

The McGrady quarry 140 

The Jamestown granite area 140 

The Oakdale Cotton Mill 141 

The Modlin quarry 142 

The Greensboro granite area 142 

The City quarry 142 

The County quarry 143 

Intrusive dike rocks of basic composition 144 

Diabase dikes 145 

Diorite 145 

Greenstone dikes 146 

Amphibolite 146 

Gabbro 146 

Alamance County 147 

The Burlington granite area 147 

The Hall place 147 

The Altamaha granite area 148 

Basic igneous rocks 149 



CONTENTS. XI 



PAGE 



Resume of the granites of the Carolina igneous belt. (The Main 

Granite Belt) 150 

The Western Piedmont gneiss and granite belt 152 

General description 152 

Surry County 152 

The North Carolina Granite Corporation. (Mt. Airy quarries) 153 

Alexander County 160 

Rocky-Face Mountain granite area 160 

Wilkes and Alleghany counties 161 

Stone Mountain granite area 161 

Stone Mountain exposure 162 

Resume of the granites of the western Piedmont granite belt. . . . 163 

The Appalachian Mountain granite area 164 

General description 164 

Buncombe County 164 

The Asheville gneiss area 165 

The City quarry 165 

The Hamilton quarry 165 

The Biltmore quarry 166 

The County quarry 166 

The DuBose quarry . 167 

The Howland quarry 167 

Swain County 167 

The Bryson City granite area 167 

McDowell County 168 

The Marion gneiss area 168 

Henderson County 169 

The Balfour granite area 169 

The Balfour Granite Company's quarry 169 

Transylvania, Jackson, and Macon counties 170 

Madison County 171 

Hot Springs granite area 171 

Unakite 172 

Granite in other counties of the mountain region 174 

Resume of the granites of the mountain region 175 

Chapter III. — Dikes and veins penetrating the crystalline rocks of 

North Carolina 176 

Joint structures 177 

Slickensides 178 

Dikes of basic composition intersecting the granites 178 

Acid dikes and veins penetrating the granites 179 

Pegmatites 179 

Aplite 180 

Granite dikes 180 

Quartz veins 181 

Relationship between the jointing and the dikes 182 

Age relations of the basic dikes 183 



Xll CONTENTS. 

PAGE 

Table showing the distribution and strike of dikes of basic eruptive 

rocks of the main granite belt of the Piedmont plateau region 184 

Table showing the strike of the joints penetrating the granites of the 

main granite belt of the Piedmont plateau region 185 

Table showing the distribution and strike of the dikes of basic 
eruptive rocks of the coastal plain and the northeastern 
Piedmont belt 186 

Table showing the strike of the joints penetrating the granites of the 

coastal plain and the northeastern Piedmont belt 187 

Chapter IV. — The calcareous rocks, limestones, and marbles 188 

Varieties 188 

Structure 189 

Weathering qualities 189 

Methods of working and quarrying 190 

Uses 190 

Marble 190 

Geographical distribution . 190 

Cherokee County 192 

The Culberson quarry 193 

The Kinsey quarry 194 

The National Marble Company's quarry 195 

Swain County 200 

McDowell County 202 

Mitchell County 203 

Limestone • 205 

Southeastern area 205 

Piedmont and mountain areas 207 

Chapter V. — The serpentines and verdantique marbles 210 

Structure 211 

Weathering qualities 211 

Uses 212 

Geographical distribution 212 

Buncombe County 212 

Wilkes County 214 

Madison County 214 

Wake County 215 

Chapter VI. — Sandstones and quartzites 216 

Varieties 216 

Structure 217 

Weathering qualities 217 

Quarrying and working 218 

Uses 218 

Geographical distribution 218 



CONTENTS. Xlll 

PAGE 

Anson County 219 

Wadesboro area 219 

The Old Linehan quarry 219 

The W. A. Polk quarry (formerly the Wadesboro Brown- 
stone Company's quarry) 220 

The Frank Hammond quarry 221 

The W. Parsons' quarry 222 

The S. H. Horton's quarry 222 

Moore County 223 

Carthage area 223 

The Sanford area 227 

The Carrington-Gonella quarry 227 

The Rackle and Lawrence quarry 228 

Chatham County 229 

Orange County 230 

Wake County 231 

Durham County 232 

Stokes and Rockingham counties 234 

Tests on Sanford and Wadesboro sandstones 234 

Chapter VII. — Dikes penetrating the sandstones 237 

Anson County 238 

Chatham County 238 

Durham County 239 

Moore County 239 

Orange County 240 

Table showing the distribution of dikes penetrating the sandstones 

and their relation to the jointing 241 

Chapter VIII. — Methods of quarrying stone 244 

Remarks on the opening of new quarries 249 

Chapter IX. — The weathering of building stone 254 

The testing of building stone 255 

Table showing strength per square inch, specific gravity, weight per 

cubic foot, and ratios of absorption of stone of various kinds. 257 

Shearing tests 258 

Elasticity test 258 

Ratios of expansion and contraction 258 

Absorptive power and resistance to freezing 259 

Fire tests 260 

Corrodibility and color tests 260 

Abrasive tests 261 

Appendix. — Stone for road building 262 

Table showing results of tests made on North Carolina stone suitable 

for road metal 265 



ILLUSTRATIONS 



PLATE FACING PAGE 

I. Granite quarries, Mt. Airy, Surry County 1 

II. A, Micro-structure of granite, Mt. Airy, Surry County; B, Micro- 
structure of gabbro, Barber Junction, Rowan County 10 

III. Physiographic map of North Carolina 12 

IV. A, Weathered granite in railroad cut west of Lilesville, Anson 

County; B, Decomposed diabase dike in porphyritic granite, 

Lilesville 16 

V. A, Residual decay derived from the weathering of porphyritic 
granite 1 mile west of Lilesville, Anson County; B, Granite 
dike penetrating decayed rock 1 mile west of Woodleaf, 
Rowan County 20 

VI. Map showing geographic distribution in North Carolina of 

granite and gneiss 30 

VII. A, City quarry, Charlotte, showing development of joints pene- 
trating the granite; B, Diabase dike penetrating granite at 

City quarry, Charlotte, N. C 68 

VIII. A, Photograph of fresh surface of leopardite, showing the stone 
when broken at right angles to the long parallel streaks or 
pencils of a dead black color; B, Photograph of a section 
of the leopardite cut parallel with the direction of the 
pencils 72 

IX. A, The Breed quarry iy 2 miles southwest of Mooresville, Iredell 
County; B, Boulder outcrop of augite-syenite 4 miles south- 
west of Concord, Cabarrus County 82 

X. A, Balfour Quarry Company's quarry in augite-syenite 3% miles 
southwest of Concord, Cabarrus County; B, Granite boulder 
outcrop, Dunns Mountain, 4 miles east of Salisbury, Rowan 
County 94 

XL A, Boulder quarry on Phillips Mountain 1 mile southwest of 
Faith, Rowan County; B, Bare surface exposure of granite 
on the northeast slope of Dunns Mountain, Rowan County. 102 
XII. A, Dunns Mountain Granite Company's quarry exposing fresh 
and decayed granite; B, Quarry No. 2 of the Rowan Granite 
Company A x / 2 miles southeast of Salisbury 104 

XIII. Rowan Granite Company's quarry near the Yadkin Railroad 

iy 2 miles southeast of Salisbury, N. C 106 

XIV. Rowan Granite Company's quarry, showing thickness of granite 

sheets that are cleaved and quarried 108 



ILLUSTRATIONS. 



XV 



PLATE 

XV. 



XVI. 



XVII. 



XVIII. 

XIX. 
XX. 



XXI. 



XXII. 

XXIII. 



XXIV. 



XXV. 
XXVI. 



XXVII. 
XXVIII. 

XXIX. 
XXX. 

xxxi. 

XXXII. 



FACING PAGE 

Rowan Granite Company's quarry 4^ miles southeast of Salis- 
bury, Rowan County, showing decayed granite and the 
amount that is stripped 110 

A, Quarry of the Balfour Quarry Company in the pink granite 
of Dunns Mountain, Rowan County; B, Cutting shed of 
Balfour Quarry Company, with large block of pink granite . 112 

A, Quarry No. 1, Rowan Granite Company, iy 2 miles southeast 
of Salisbury, showing granite decayed to a depth of 10 ft.; 
B, Boulder outcrop of orbicular gabbro-diorite, Hairston 
farm, Davie County, 10 miles west of Lexington, Davidson 
County 130 

Photograph of polished surface of orbicular gabbro-diorite, 

showing the spheres of dark green hornblende. 132 

General view Mt. Airy granite quarries 152 

North Carolina Granite Corporation's quarry iy 2 miles north 
of Mt. Airy, Surry County, showing method of stripping 
and working off the surface shelf from a part of the ridge 
slope 154 

A, North Carolina Granite Corporation's quarry, Mt. Airy, 
Surry County, showing thickness of sheets as worked; B, 
Rocky-Face Mountain 4 miles northeast of Hiddenite, 
Alexander County, an unreduced residual of granite-gneiss . 156 

Cemetery entrance at Lancaster, Pa., made of Mt. Airy granite. 158 

A, General view of power house, cutting sheds, and offices of 
The North Carolina Granite Corporation, Mt. Airy; B, 
Interior of cutting shed of The North Carolina Granite 
Corporation 160 

Extensive bare surface exposures of granite over a ridge slope 
worked by The North Carolina Granite Corporation 1% 
miles north of Mt. Airy, Surry County 162 

Stone Mountain, Wilkes County, 18 miles northwest of Elkin. . 164 

A, View of marble quarry of the National Marble Company at 
Regal, Cherokee County; B, Quarry of National Marble 
Company, Regal, showing channellers at work 196 

A, Micro-structure of marble from Hewitts, Swain County; 
B, Micro-structure of sandstone from Wadesboro, Anson 
County 200 

A, Lime kilns of the Blue Ridge Lime Company, at the Lance 
quarry, 2 miles north of Fletcher; B, Chimney built in 1846 
with mortar made from lime obtained from the limestone 
of the Lance quarry 208 

Map of central portion of North Carolina, showing distribution 

of the Triassic sandstones 218 

A, The Carrington-Gonella sandstone quarry near Sanford, 
N. C; B, Post-office building, Wilmington, built of sand- 
stone from near Wadesboro, Anson County 228 

Forms assumed by 2-inch cubes of sandstone after subjection 

to crushing test 236 

View to illustrate excessive jointing in a quarry 252 



XVI ILLUSTRATIONS. 

FIGURE PAGE 

1. Map showing the favorable position of North Carolina relative to 

markets for building stones 7 

2. Diagrams illustrating method of cleaving by compressed air; B, 

Lift or Drill Hole; BC, Area Cleaved by Powder; AFF, Area 
Cleaved by Compressed Air; DE, Thin Edge on down hill side 
of quarry, where air escaped 159 

3. Map of western portion of North Carolina, showing distribution of 

marble beds 191 

4. Pegmatitic dike (c) cutting the Mitchell County marble (&); the 

country rock is a contorted typical mica schist (a), which at 

the contact with marble is quite calcareous 204 

5. Eclipse rock drill 245 

6. Ingersoll-Sergeant quarry bar drill 246 

7. Wardwell channelling machine 247 

8. Ingersoll-Sergeant channelling machine 248 

9. Ingersoll-Sergeant undercutting machine 249 

10. Dallett pneumatic stone surfacing machine 251 

11. Drill holes in strata, showing how erroneous ideas a thickness of 

bed accepted by boring, a, Horizontal strata; &, inclined strata; 

c, vertical : 253 



PREFACE 



The following report on the Building and Ornamental Stones of North 
Carolina is not claimed to be either exhaustive or final; but has been 
published at the present time in order to call attention to the economic 
value of the building stones of North Carolina, their location and their 
commercial possibilities. The evidence at hand shows the State to be 
well supplied with a great variety of building stone materials, particu- 
larly those of a granitic type. With perhaps the possible exception of 
Georgia, it is better supplied both as regards quality and variety than 
any of the other Appalachian States south of New England. This is an 
important fact and taken in connection with the mildness of the climate, 
which permits a long season of outdoor labor, and the cheapness of labor 
itself, should result in the development of a very extensive industry. 

The field work for this report was done by Dr. Thomas L. Watson and 
Mr. Francis B. Laney, commencing during the summer of 1903. Mr. 
Laney began work the latter part of May, 1903, and continued either in 
the office or the field until the end of January, 1904. There was no 
further field work done until the summer of 1905, when Mr. Laney spent 
a portion of the summer in the field, visiting a few areas and re-visiting 
some of the more important quarries that had been studied in 1903, noting 
further development and additional equipment. Thus the report pre- 
sents the status of the stone industry of the State at the beginning of 
July, 1905. 

Dr. Watson entered the field early in June, 1903, and finished soon 
after the first of September. He continued his studies, however, on 
the petrography of the granites and gneisses, and all the petrographic 
work, together with a large portion of the manuscript relating to the 
siliceous crystalline rocks, has been prepared by him. The field work, 
as far as possible, was divided, Mr. Laney devoting the larger part of his 
time to the marbles, sandstones, serpentines, and road materials; while 
Dr. Watson worked almost exclusively on the granites and g v neisses, with 
incidental reference to the associated eruptives, the, diorites, diabases, 
and gabbros. In connection with this, he was assisted for a period of six 
2 



XV111 PREFACE. 

weeks by Mr. Laney, who visited the more remote regions of the State 
and those localities most difficult of access. Dr. Merrill was only able to 
make five trips into the field, principally in the summers of 1903 and 
1905, and, on account of other duties, was obliged to content himself 
with going over somewhat hastily such areas visited by the others; 
especially those which afforded an opportunity for differences of 
opinion. In all instances he found the opinions expressed safe and the 
work well and conscientiously done. 

In connection with this investigation on the building stones, there 
have been but few tests made to ascertain resistance to crushing, shearing, 
elasticity, or absorption, chiefly because the present bulletin is a prelimi- 
nary report calling attention to the deposits of stone, especially those 
of known economic importance, and indicating how these can be opened 
and operated profitably. There have been a few tests made with a view 
to ascertaining the possible loss of strength of sandstone through absorp- 
tion of water and freezing, which are given on pages 235-6. No chemical 
analyses were attempted, nor were they for the most part considered 
essential for the work at hand, as Dr. Merrill still adheres to his opinion 
that pressure tests in themselves alone are of little value and that more 
can be learned from an examination in the field than through all known 
laboratory tests taken together. Many of the chemical analyses that 
have been used were taken from the First Biennial Eeport of the North 
Carolina Geological Survey, 1 which contains a short paper by Professor 
J. V. Lewis on the Building and Ornamental Stones of the State. 

In the preparation of the maps for this report, the resources of the 
United States Geological Survey were drawn upon whenever possible, the 
work of Mr. Arthur Keith proving especially valuable. The tests of 
road materials were made under the direction of Mr. Logan Waller Page, 
of the Department of Agriculture, and those for resistance to crushing by 
Mr. H. S. Betts, of the Bureau of Forestry. The photographs of the 
crushed cubes were kindly furnished by Mr. B. J. Howard, the Micro- 
scopist of the same department. 

The field of investigation covered by this report has been touched upon 
by various workers, beginning with Dennison Olmstead in 1824. The 
most important investigations that have been made, however, were those 
by Professors W. C. Kerr and J. Volney Lewis. Appropriate references 
to the writings of these gentlemen are made in the text. 

1 First Biennial Report, N. C. Geological Survey, 1891, pp. 61-103. 



PREFACE. XIX 

Acknowledgments are also due to The North Carolina Granite Cor- 
poration, of Mt. Airy, for valuable information and many courtesies; to 
the Balfour Quarry Company, of Asheville, for personal assistance, infor- 
mation, etc. ; to Mr. D. A. McDonald and Col. A. H. McNeill, of Carthage, 
for assistance and information regarding the sandstones of Moore County. 

Joseph Hyde Pratt, 

State Geologist. 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE I 




THE BUILDING AND 01 
OF NORTH CA1 






[Omas L. Watson, an d 
with tij 

George I 



CHAPTER I. 

PB 

^ENTIAL QUALITIES OF BUIL 

A stone, in order 
quantity, be readily an< 
distance of a market, i 
tion facilities. It must als< 
it desirable or, at least, unol 
ities as shall enable it to ■■.< 

alls of a building for a pi 
intended for inl 
cation is less 

for interior work only, the weathi 
most essential to be eonside- 

The matter of quantity I 
few types, such as are known con: 

larble, and linn 
will be given later. Such occui 
. 

ruder 

■ 






it upon 

item. Id 

uated at or near the ; 



aeiss, 

uportant 
or on 



THE BUILDING AND ORNAMENTAL STONES 
OF NORTH CAROLINA. 

By Thomas L. Watson and Francis B. Laney, 

WITH THE COLLABORATION OF 

George P. Merrill. 



CHAPTER I. 

PRELIMINARY GENERALITIES. 

ESSENTIAL QUALITIES OF BUILDING STONE. 

A stone, in order to be available for bnilding purposes, must exist in 
quantity, be readily and cheaply quarried, and occur within a reasonable 
distance of a market, or in a position especially favored by transporta- 
tion facilities. It must also be of a color and texture such as to render 
it desirable or, at least, unobjectionable, and possess, further, such qual- 
ities as shall enable it to withstand all the vicissitudes of exposure in 
the walls of a building for a prolonged period. In the case of a stone 
intended for interior and purely decorative work, the last-named qualifi- 
cation is less important, but as few stones can be worked economically 
for interior work only, the weathering quality of a stone is one of the 
most essential to be considered. 

The matter of quantity has limited the selection to a comparatively 
few types, such as are known commonly under the names granite, gneiss, 
sandstone, marble, and limestone — names the full significance of which 
will be given later. Such occur widespread, both geographically and 
geologically. There are few localities that are not provided by nature 
with a local supply of building stone of some sort, though it may be of 
such a nature as to render it advisable to bring in better material from 
a distance. Accessibility and ready means of transportation are naturally 
important matters. Stone is heavy and expensive to handle; and to put 
it upon the market with as little handling as possible is an important 
item. In the early history of quarrying in America those quarries sit- 
uated at or near the water's edge, as along the coast of Maine, or on 



2 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

navigable rivers, naturally had a great advantage, but the rapid increase 
of railroad facilities has largely done away with this, and extensive and 
important quarries are now worked far inland and remote from Avater 
transportation. 

Naturally, a stone for use in any but rough construction must work 
freely and safely. There is a greater difference in stones, even of the 
same kind, in this respect than is ordinarily supposed. As a rule, the 
granitic and trappean rocks are the most expensive to work, but the rule 
is by no means without exception, since much depends upon the degree 
of development of those properties common to nearly all stones, of break- 
ing with comparative ease along two directions at right angles with each 
other and known as rift and grain. The rift is, as a rule, horizontal or 
parallel to the original bedding of the stone, if such it may have had; 
the grain is less perfect than the rift, is at right angles to it and in a 
vertical direction. Stones in which these qualities are well-developed 
can often be worked more economically than others which may be softer. 
In a general way, a stone of fine and even grain will be found to work 
more readily than one that is coarse. The same is true of its weathering 
qualities. A stone which is a mixture of hard and soft particles is rarely 
suitable for polished or finely finished work. Veined stones, on account 
of the differing character of the vein matter and that composing the bulk 
of the rock, often work with great difficulty, the veins proving, moreover, 
sources of great weakness, though such may add variety and beauty to 
the stone. 

The colors found in stone are mainly the quiet tones. Among granites 
the grays preponderate, though pink and red varieties occur; among 
marbles pure white, through blue-gray, to black; pink, yellow, and red 
colors are also found. Among sandstones the gray, buff, brown, and 
red-brown are most common. The suitability of any particular color is 
largely a matter of taste and, as such, need not be discussed here. 

The matter of color of a rock, when first quarried, after prolonged 
exposure, and after working, is one that should, however, be considered 
in some detail. Among siliceous crystalline rocks the colors are due 
mainly to the presence of colored minerals or to the physical condition 
of the feldspars. Thus, the gray color of granites is due largely to an 
admixture of white feldspars and black mica or hornblende ; the red colors 
to red feldspars; the dark greenish, sometimes almost black colors to 
clear, pellucid feldspars; and the white, to white feldspar. The dark 
colors of the diabases and the gabbros are due to the pellucid feldspars 
and the dark pyroxenes they carry. Pure limestones and dolomites are 
white simply because that is the color of the calcite or dolomite which 



PRELIMINARY GENERALITIES. 3 

forms their chief constituent. The dark color common in this class of 
rocks is due to the presence of carbonaceous matter; the red to iron 
oxide, though the pink and red colors of some of the onyx marbles 
seems to be due, in part, also to organic matter. The red, brown, and 
yellow colors of sandstones are due to iron oxides. The changes in color 
which these rocks are likely to undergo on exposure are noted in the 
remarks on rock weathering. It may not be out of place 'to state here, 
however, that nearly any feldspathic rock is likely to become lighter in 
color during the incipient stages of weathering, owing to the opening 
up of the cleavage planes in the feldspars. It is for this same reason 
that the hammered surface of a rock of this type is of a lighter color 
than the natural rock face or polished surface. The impact of the 
hammer breaks up the granules on the immediate surface, not, it may 
be to the point of immediate disintegration, but enough so that the light 
falling upon the surface is reflected, instead of absorbed, and the resultant 
effect upon the eye is that of whiteness. The darker color of a polished 
surface is due merely to the fact that, through careful grinding, all these 
irregularities and reflecting surfaces are removed, the light penetrates 
the stone, is absorbed, and the effect upon the eye is that of a more or 
less complete absence of light, or darkness. Obviously then, the more 
transparent the feldspars and the greater the abundance of dark minerals, 
the greater will be the contrast between hammered and polished sur- 
faces. This is a matter worthy of consideration in cases where it is 
wished, as in a monument, to have a polished die, surrounded by a 
margin of hammered work to give contrast. Often, when a piece of work 
of this nature is exposed, the contrast between hammered and polished 
work diminishes slightly, owing to the gradual weathering out of the 
particles splintered through hammering. The contrast is less when the 
stone is wet than when dry, because the water fills all the little rifts and 
crevices and, by its refracting power, tends to produce the same effect 
as though the stone were polished. 

SURFACE FEATURES OF THE STATE. 

The State of North Carolina, considered with reference to its surface 
features— its physiography, as it is ordinarily termed — may be divided 
into three parts : A western or mountain region ; a central, submontaine 
or plateau region, usually designated as the Piedmont plateau region 
and an eastern plains region, usually designated as the coastal plain 
region. 

The first includes the rugged mountainous area extending from the 
State line eastward, to, and including the Blue Eidge. The second or 



^v 



4 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

submontaine region, known to geologists as the Piedmont plateau, oc- 
cupies the central portion of the State 1 , and extends from the Blue Eidge 
to a line which may be drawn from the western end of Northampton 
County on the north, through Richmond County on the south, to the State 
line. The third, or coastal plain region, extends from the Piedmont 
border eastward to the coast. It comprises an area of nearly two-fifths 
of the entire State and is characterized by loosely consolidated sands, 
gravels, and marls which need little consideration from the present stand- 
point. The central and western portions of the State, which include the 
Piedmont and mountain areas, are greatly diversified and abound in a 
variety of useful building-stone material. 

Eoughly speaking, the geological formations which are capable of 
yielding desirable stone for structural purposes or ornamentation traverse 
this part of the State in northeast and southwest directions. Beginning 
at the western margin of the coastal plain, there is found extending 
northeast from Raleigh a broad belt of gneissic rocks, succeeded on the 
west by one of brown sandstone, and this in order by belts of schist, 
granites, and gneisses, to the State line, the last mentioned belt carrying 
in Cherokee, Graham, and Swain counties a narrow belt of marble. 
There are numerous minor exceptions to the regular order as given above, 
which will be noted later. 

GEOGRAPHIC POSITION OF THE STATE CONSIDERED WITH 
REFERENCE TO OTHER THAN LOCAL MARKETS. 

The State of North Carolina, as described by Prof. W. C. Kerr, is 
situated on the Atlantic Slope of the Appalachian Mountains, in the 
middle latitude of the United States and halfway between Lake Erie 
and the Gulf of Mexico, being included very nearly between the parallels 
34° and 36-§° north latitude, and between the meridians 75J° and 84-J° 
west longitude, and extending from the sea coast to the crest of the 
Smoky Mountains. The extreme length of the State is more than 500 
miles, and greatest width 188 miles; its area 52,286 square miles, of 
which the eastern 20,000 square miles is included in the area referred 
to in the previous chapter as the coastal plain, a region fairly level and 
unbroken by eminences of any importance. The central portion of the 
State is a submontaine plateau with an average elevation above sea-level 
of some 1,000 feet. The western portion, as already noted, is mountain- 
ous. No navigable streams traverse the State, and except in the eastern 
sections, transportation is necessarily limited to railways. 

To appreciate in full the bearing of these facts upon the subject in 



PRELIMINARY GENERALITIES. 5 

hand, there is given here, in part, what has been elsewhere stated regard- 
ing this same subject. 1 

" The majority of stones used for any form of structural or decorative 
work may be roughly classed under three heads: (1) The crystalline 
siliceous rocks, including the granites, gneisses and diabases, or trap- 
rocks; (2) the calcareous rocks, including all limestones and dolomites, 
both the crystalline and compact common varieties; and (3) the f rag- 
mental or clastic rocks, including the sandstone and clay slates. Those 
of the first group result either as erupted molten matter from the earth's 
interior or from the metamorphism of siliceous sediments. Those of the 
second group originate mainly as deposits of calcareous mud from the 
breaking up of shells, corals, and the remains of other marine animals 
on an old sea bottom. Those of the third group result from the break- 
ing up of older rocks, and the accumulation on the bottom of lakes and 
seas of the resultant sand, clay, or mud in beds of varying thickness, to 
be subsequently hardened into stone. 

" Now the essential difference between a marble and a compact com- 
mon limestone, like those of Ohio or Kansas, is that the first has under- 
gone, through the combined action of heat and pressure, just the right 
degree of change, or metamorphism as it is technically called, to develop 
in it crystallization and color; the essential difference between a brick 
or fire clay and a cleavable slate suitable for roofing, is, as explained 
elsewhere, that the first named still retains its plastic condition as it was 
laid down in the form of fine silt on a sea bottom, while the slate has by 
geological agencies, by actual movements of the earth's crust, been so 
squeezed and compressed as to lose all resemblance to its former self, and 
become the cleavable article of commerce we now find it. 

" These processes of change, as noted above, are dependent very largely 
upon the actual movements, warpings and foldings as one might say, 
of the earth's crust and the heat and chemical action which is thereby 
generated, and since these movements take place only with extreme slow- 
ness, whole geologic ages being occupied in their inception and comple- 
tion, it follows as a matter of course that these metamorphic rocks, these 
gneisses, marbles and roofing slates, are found only among the older 
rocks and only in those portions of the country where this crust has been 
warped, compressed, and folded as in the process of mountain making. 
In other words, one need expect to find these rocks in their best develop- 
ment only in States bordering along more or less- extensive mountain 
ranges, while in the great interior plains and prairie regions they will 

1 George P. Merrill, Stones for Building and Decoration, Wiley & Sons, N. Y., 1903. 



6 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

be comparatively rare. It is of course probable, and perhaps may be 
regarded as a matter of certainty, that at great depths beneath the land 
surface in this interior region are to be found the xArchaean gneisses 
which seem to form the floor of the continent, and possibly other rocks 
metamorphosed by the heat and pressure of great depths. Being, how- 
ever, covered by many feet of later deposits, they may, for our purposes, 
be left out of consideration. Let us then consider the physical features 
of the earth's crust as found within the limits of the United States, and 
discuss briefly the various rocks so far as they are dependent upon or 
controlled by these features. 

" Let one take a map of the United States and draw a straight line 
from a point near Montreal, Canada, to the middle of Alabama. East 
of this line will lie the entire Appalachian Mountain system and with 
a few exceptions the States traversed by or bordering upon this system 
are the only States east of the Rocky Mountains containing granites, 
gneisses, diabases, crystalline calcareous rocks (marbles) or roofing 
slates. These exceptions are to be found in northern Wisconsin; in Min- 
nesota, west of Minneapolis; in small areas in southeastern Missouri, 
principally in Iron, Masidon, and St. Francois counties; the Black Hills 
in South Dakota; in a small area near Little Eock, Arkansas, and in a 
few small isolated areas in the Indian Territory and eastern Texas, as 
in Burnet County. The whole interior of the country, comprising all 
but the extreme eastern portions of West Virginia, Kentucky, and Ten- 
nessee; all of Ohio, Indiana, Illinois, Iowa, Nebraska, the Dakotas, 
Kansas, Mississippi, Louisiana, Florida, Oklahoma, and with the excep- 
tions above noted, all of Missouri, Arkansas, and eastern Texas, though 
containing sandstones and limestones of the common and oolitic types, 
produce neither granite, gneiss, trap-rocks, nor slates, nor, except in small 
quantities, anything that can be called a marble. The earth's crust 
throughout this entire area has been little changed or disturbed by the 
eruption of molten rocks or by the processes of mountain making. The 
sedimentary rocks remain little altered, or if metamorphosed, they have 
been, and still remain, covered by later deposits. 

" It does not necessarily follow, however, that all the rocks east of this 
line, as drawn above, have undergone metamorphism. On the contrary, 
there remain many areas of rock little changed, and in some cases it is 
possible to trace beds of unaltered limestone till they pass into the pure 
white marble. It has thus been shown that the pure white statuary 
marble of Carrara, Italy, was once a common fossiliferous limestone, but 
which has become converted into marble by the heat and pressure in- 
cident to the formation of the Apennine Mountains. 



PRELIMINARY GENERALITIES. 




Fig. 1. — Map showing the favorable position of North Carolina relative to markets for 

building stones. 



8 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

" Hence it is that mountainous countries as a rule contain a greater 
variety of material than do the level prairie regions. Nature makes her 
own compensations, and if by mountain building or glacial erosion she 
has rendered a country unfit for cultivation, she has as a rule rendered 
an equivalent by furnishing and rendering accessible through the same 
agencies inexhaustible supplies of building stone, anthracite coal, copper, 
iron, and the ores of the precious metals." 

Confining then our attention to the Atlantic States south of Penn- 
sylvania, we find granite and allied rocks, both eruptive and metamorphic 
occurring in Maryland, Virginia, North and South Carolina, Georgia, 
and Alabama. Granites are extensively worked in Maryland, principally 
at Guilford and Woodstock ; in Virginia near Petersburg and Eichmond ; 
in North Carolina near Mount Airy and Salisbury; in South Carolina 
near Winnsboro; and in Georgia at Stone Mountain and other regions 
southeast of Atlanta. Marbles also are known to occur in each of the 
above named States with the exception of South Carolina, but are 
quarried in quantity only in Maryland and Georgia. Sandstones of 
more than local importance have thus far been reported only from Mary- 
land, North Carolina, and Virginia. It is thus apparent that North 
Carolina is very favorably situated, since her resources include granite 
and gneisses, trappean rocks, some of which are worthy of being included 
as black granites ; marble ; compact, common limestone ; sandstones ; and 
serpentine. 

Further than this we have to consider the question of market. A 
glance at the map (fig. 1) shows that the cities of the Atlantic seaboard 
can draw their supplies from any of the States accessible by rail and 
water routes of transportation. The great interior plains region is, 
however, by no means so readily supplied with a diversity of local mate- 
rial nor so accessible. West of the Ohio river and the Cumberland 
plateau, south of the Great Lakes and north of the Gulf of Mexico, the 
product is limited wholly to sandstone and limestone of the common or 
oolitic type. Nothing of the nature of a marble lies within this area 
east of the front range of the Eocky Mountains, and granite rocks only 
in the isolated areas near Hot Springs in Arkansas, the Iron Mountains 
of Missouri, and yet unexploited areas in Indian Territory, Oklahoma, 
and Texas. The hundreds of large and prosperous cities and towns in- 
cluded within this area will afTord a market for a far larger amount than 
the State is now supplying, and the development of the quarry industry 
on a much larger scale than that at present is possible without danger 
of ruinous competition. 



CHAPTER II. 

THE VARIETIES OF BUILDING STONES. 

THE GRANITES, GNEISSES, AND ASSOCIATED CRYSTALLINE 
SILICEOUS ROCKS. 

Definition. — Under the name of granite are included a series of rocks 
of eruptive origin, consisting essentially of the minerals quartz and ortho- 
clase feldspar, though nearly always carrying in addition some plagio- 
clase feldspar, more or less mica, and sometimes hornblende or pyroxene. 
The North Carolina granites are largely mica granites, and since this 
mica is the black variety, biotite, they may be designated as Inotite 
granites. Other varieties occur, as will be noted in the detailed descrip- 
tions. Beside the minerals, mentioned, others like epidote, allanite, 
sphene, apatite, magnetite, and pyrite may occur, but with the exception 
of the last named they have little significance from our present stand- 
point. By closely examining a piece of granite of ordinary texture, it is 
usually possible to determine the more important minerals even without 
the aid of a microscope. The most conspicuous mineral is usually the 
feldspar which is characterized by its faculty of splitting or cleaving in 
two definite directions almost at right angles with each other, the cleaved 
surfaces being almost perfectly flat and smooth. The mineral is usually 
of a white, gray, or pinkish color. The quartz occurs only in irregular 
granules between the feldspars, is of a gray color, or quite colorless and 
breaks, not with smooth surfaces like the feldspars, but with conchoidal 
fractures, like glass, which indeed it closely resembles, being almost 
transparent. The mica is easily recognizable from its coal black color, 
or brown color when seen in very thin flakes, and from its splitting up 
very easily and readily into thin folise or sheets. 

Structure. — When submitted to close inspection in thin sections under 
a microscope, the granites are found to be made up wholly of crystalline 
granules closely in contact, and often interknit, as shown in A of PL II. 
All varieties of texture occur from those so fine that the individual 
mineral can scarcely be determined without the aid of the microscope to 
those in which some of the constituents may be an inch or more in length. 
When large feldspars occur with or without quite perfect crystal outlines 
imbedded in a ground mass of finer, more granular minerals, the rock 



10 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

is said to be porphyritic and the porphyritic minerals are themselves re- 
ferred to as phenocrysts. 

Color. — The color of the granites is usually some shade of gray, though 
pink or red varieties are not uncommon. The colors are dependent 
largely upon the relative abundance of the mica and the character of the 
feldspars. Those granites containing a large proportion of black mica 
are naturally of a darker gray color than those containing but little. The 
pink and red colors are due to the presence of pink and red feldspars. 

Weathering Qualities. — When exposed in the walls of a building, gran- 
ites are susceptible to unfavorable changes mainly through disintegra- 
tion by expansion and contraction of the constituent minerals, as already 
noted on page 3. Being composed almost wholly of siliceous minerals, 
chemical agencies, such as solution and oxidation, are as a rale of minor 
importance. In some instances the rocks contain pyrite which oxidizes 
and stains the stone an unsightly rusty color. More rarely the black 
mica undergoes decomposition, though this occurs only after many years 
exposure. The disintegration through heat and frost usually manifests 
itself first on the feldspars, which split up, or at least separate into thin 
folise along the lines of cleavage, to which reference has already been 
made. The separation between two cleavage lamina? may be but a 
thousandth of an inch, but as it allows the penetration of moisture from 
rains such a change renders the stone susceptible to the unfavorable ac- 
tion of frost. The black mica is susceptible to the same changes, and 
its presence in too great profusion is a detriment, rendering the stone 
weaker, more difficult to polish, and not likely to retain its lustre when 
once polished. 

Since then the preliminary stages of decomposition in granites aTe 
those of disintegration, it is evident that a rock in which the particles 
are closely dovetailed or interknit will be more lasting than one of a 
granular structure (see Pis. IV and V). 

In connection with the granites, it is necessary to consider also certain 
rocks of the same mineral composition but differing in that they possess 
a banded or foliated structure due to the arrangement of their constituent 
minerals in more or less parallel bands, or folia?. Such rocks are known 
as gneisses, or sometimes by the quarrymen as bastard granites. 

On account of the parallel arrangement of the minerals, the gneisses 
work very unevenly in different directions and cannot be utilized for 
high grade, finely dressed work. For massive masonry, bridge abut- 
ments, they are often, however, fully equal to the granites. 

Under the name of black granite, and trap, it is customary to include 
a series of igneous rocks, occurring mostly in the form of dikes, which 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE II 




A. MICRO-STRUCTURE OF GRANITE, MT. AIRY, SURRY COUNTY. 




5. MICRO-STRUCTURE OF GABBRO, BARBER JUUNCTION, ROWAN COUNTY. 



THE VARIETIES OF BUILDING STONES. 11 

differ widely from the granites in their mineral composition, containing 
neither quartz nor orthoclase feldspar, but consisting essentially of 
plagioclase feldspar and the minerals augite, hornblende, and sometimes 
olivine and mica. Such are properly classed as gabbros, diabases, dior- 
ites, etc. The working qualities of these rocks are as a rule much in- 
ferior to the granites, and their colors much too sombre for any but 
monumental purposes, and for road construction. 

The rock at Barber junction on the Southern Eailway 12 miles north- 
west of Salisbury is a good example of the better class of these rocks 
(see p. 119). 

Quarrying and Working. — Stones of the granitic type can be econom- 
ically quarried only with the use of powder, the freed blocks being 
afterward worked up by plug and feather splitting, and by hand ham- 
mers and chisels. The great hardness of the material largely precludes 
the use of steam channellers or of saws for cutting it into blocks and 
slabs, as is done with marbles and many sandstones. Fortunately the 
great toughness of the rock renders it only remotely liable to injury 
through blasting. Machines have been invented and are in use for plan- 
ing, polishing, and even turning columns of granite in some of the large 
eastern works, but such as yet have scarcely been introduced into North 
Carolina. 

Uses. — The granites are among the strongest, most massive and dur- 
able of natural building materials, and all things considered, are perhaps 
better adapted to a wider range of structural and ornamental uses than 
any other stones. The crushing strength of rocks of this type varies as 
a rule from 15,000 to 25,000 pounds, as shown in the table on p. 156. 
These figures are so far beyond anything demanded in ordinary structures 
that this feature can be safely ignored. The colors are as a rule 
cold, but the appearance of strength which such impart to a build- 
ing will always render them desirable, particularly in massive structures. 
The introduction of machinery into stone working, moreover, renders 
possible the production of polished surfaces for columns, pilasters, and 
wainscotings. Being massive throughout, without rift or grain devel- 
oped sufficiently conspicuous to be detected by the ordinary observer, the 
granites are eminently adapted for columns, monuments, and other 
structural forms that are to be viewed from all sides, and in which, as a 
consequence, bedding lines, or other blemishes would be unsightly. 

GEOGRAPHIC DISTRIBUTION OF THE GRANITES, GNEISSES, AND 
ASSOCIATED CRYSTALLINE ROCKS. 

Introduction. — The granites of North Carolina are distributed over 
about one-half the total area of the State, but the productive part of 



12 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

this area is considerably less. Openings from which more or less granite 
has been quarried in the past have been made in a majority of the 
counties in which granites occur, but at the present time less than a dozen 
quarries are being systematically worked. The quarries in active opera- 
tion during the summer of 1905 were confined principally to three areas, 
namely, the Greystone-Middleburgh area in Vance County; the Dunn's 
Mountain area, including the quarries in the vicinity of Faith Post- 
Ofnce, in Eowan County; and the Mount Airy quarries in Surry County. 
Numerous smaller quarries were worked somewhat irregularly during 
the summer in many localities over the State, principally to supply 
crushed stone for macadam on the streets and roads in the various towns 
and counties. 

Geographically, the distribution of the granites and gneisses is into 
the three larger physiographic provinces of the State, namely, the coastal 
plain, the Piedmont plateau, and the Appalachian Mountains. The 
larger part of the granites, however, are comprised within the limits of 
the Piedmont plateau region. Smaller workable areas of massive gran- 
ites, usually of excellent grade, are distributed through a number of 
counties along the inner margin of the coastal plain. The large areas 
of granite rocks distributed over the mountain region are usually schis- 
tose in structure and seem less desirable for certain high grades of work 
in which granites are used. The distribution of the granites and gneisses 
in the State is indicated on the map, PI. VI. 

Geologically the Piedmont region is divided into a number of belts, 
which, with one exception, contain larger or smaller areas of granitic 
rocks. For convenience of description the general area in the State con- 
taining granites and gneisses may be divided into the following belts, the 
location of which is indicated on the accompanying map 1 (PI. III). 
I. The Coastal Plain Eegion. 
II. The Piedmont Plateau Eegion. 

(1) The Northeastern Carolina Granite Belt. 

(£) The Carolina Metamorphic Slate and Volcanic Belt. 

(3) The Carolina Igneous Belt. (The Main Granite Belt.) 

(4) The Western Piedmont Gneiss and Granite Belt. 
III. The Appalachian Mountain Eegion. 

It will be observed that this division of the State into belts is essen- 



1 Kerr, W. C, Geology of North Carolina, 1875, Vol. I ; and accompanying map. See, 
also maps accompanying the subsequent reports of the North Carolina Geological 
Survey. 






N. C. GEOLOGICAL 



BULLETIN NO. 2. PLATE III 



3ASTAL PLAIN REGION 




^ 



12 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

this area is considerably less. Openings from which more or less granite 
has been quarried in the past have been made in a majority of the 
counties in which granites occur, but at the present time less than a dozen 
quarries are being systematically worked. The quarries in active opera- 
tion during the summer of 1905 were confined principally to three areas, 
namely, the Greystone-Middleburgh area in Vance County; the Dunn's 
Mountain area, including the quarries in the vicinity of Faith Post- 
Office, in Eowan County; and the Mount Airy quarries in Surry County. 
Numerous smaller quarries were worked somewhat irregularly during 
the summer in many localities over the State, principally to supply 
crushed stone for macadam on the streets and roads in the various towns 
and counties. 

Geographically, the distribution of the granites and gneisses is into 
the three larger physiographic provinces of the State, namely, the coastal 
plain, the Piedmont plateau, and the Appalachian Mountains. The 
larger part of the granites, however, are comprised within the limits of 
the Piedmont plateau region. Smaller workable areas of massive gran- 
ites, usually of excellent grade, are distributed through a number of 
counties along the inner margin of the coastal plain. The large areas 
of granite rocks distributed over the mountain region are usually schis- 
tose in structure and seem less desirable for certain high grades of work 
in which granites are used. The distribution of the granites and gneisses 
in the State is indicated on the map, PI. VI. 

Geologically the Piedmont region is divided into a number of belts, 
which, with one exception, contain larger or smaller areas of granitic 
rocks. For convenience of description the general area in the State con- 
taining granites and gneisses may be divided into the following belts, the 
location of which is indicated on the accompanying map 1 (PI. III). 
I. The Coastal Plain Eegion. 
II. The Piedmont Plateau Eegion. 

(1) The Northeastern Carolina Granite Belt. 
(£) The Carolina Metamorphic Slate and Volcanic Belt. 

(3) The Carolina Igneous Belt. (The Main Granite Belt.) 

(4) The Western Piedmont Gneiss and Granite Belt. 
III. The Appalachian Mountain Eegion. 

It will be observed that this division of the State into belts is essen- 

1 Kerr, W. C„ Geology of North Carolina, 1875, Vol. I ; and accompanying map. See, 
also maps accompanying the subsequent reports of the North Carolina Geological 
Survey. 



Worth /© . , 
Eta* y a * oZ * 



K. C. GEOLOGICAL SURVEY 




THE VARIETIES OF BUILDING STONES. 13 

tially the same as that adopted by the State Geological Survey/ and the 
map accompanying this report is the one compiled from the records of 
the State Survey to accompany Nitze and Hanna's report on the Gold 
Deposits of North Carolina. 3 

Previous Description. — The following are the more important papers 
which refer to the granites and gneisses of North Carolina: 
Keith, Arthur, Geologic Atlas of the United States. The Cranberry 
Folio, North Carolina-Tennessee. U. S. Geological Survey, 1903. 
Geologic Atlas of the United States. The Asheville Folio, North 
Carolina-Tennessee. U. S. Geological Survey, 1904. 
Kerr, W. C, The Geology of North Carolina, 1875, Vol. I; p. 325; Ap- 
pendix 120 pages. For building stones see especially p. 302, et seq. 
Kerr, W. C. and W. H., Description of Quarries and Quarry Kegions, 
North Carolina. Tenth Census Report, Yol. X; pp. 181-186; 
especially pp. 182-185. 
Lewis, J. V., Notes on Building and Ornamental Stones. First Biennial 
Eeport of the State Geologist. North Carolina Geological Survey, 
1891- ? 92 (1893), pp. 57-107; for granites and gneisses see especially 
pp. 75-95. 
Merrill, George P., The Collection of Building and Ornamental Stones 
in the U. S. National Museum: A Handbook and Catalogue. Smith- 
sonian Report, 1886, Part II. National Museum, pp. 277-648; for 
granites and gneisses of North Carolina, see pp. 574-576. 
Merrill, George P., Stones for Building and Decoration, New York, 
1897, 2nd Edition, p. 506. For granites and gneisses of North 
Carolina, see pp. 257-260. 
Pratt, Joseph Hyde, The Mining Industry in North Carolina for 
1901, 1902, 1903, and 1904; see pp. 76, 18, 54, and 68 respectively 
for granites. 
The authors have not had access to all of the earlier reports of the 
North Carolina Survey, but many of the later ones, particularly those 
relating to the ore-deposits, incidentally contain some mention of the 
rocks in the State that are of economic importance. 4 Such other refer- 
ences as have been published on individual areas in the State are made in 
their proper place in the body of the text. 

2 Maps published by N. C. Survey from 1891 to date ; and Kerr, W. C, Report for 
1875, Vol. I. 

3 Bulletin No. 3, N. C. Geol. Survey, 1896. 

*The report by Nitze and Hanna (Bulletin No. 3, 1896) and by Nitze and Wilkens 
(Bulletin No. 10, 1897) on the Gold Deposits of North Carolina have added much to 
our knowledge of the bed-rock geology of the State. Many references to granites and 
gneisses, particularly in their relations to the gold deposits, are contained in these 
reports. 
3 



14 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

THE GRANITES OF THE COASTAL PLAIN" REGION. 

GENERAL GEOGRAPHIC AND GEOLOGIC DESCRIPTION. 

The coastal plain in North Carolina extends inland from the coast for 
a distance of 120 to 160 miles with an approximate area of 25,000 square 
miles, which is slightly less than one-half the total area of the State. 5 It 
is composed of unconsolidated clays, sands, and gravel of recent geologic 
age. Except along the inland margin of the plain, the type of topography 
is mainly that of a low, flat, featureless plain, so typical of the Atlantic 
coastal plain region in general. Along and near its contact with the 
rocks of the Piedmont plateau the topography in places is somewhat roll- 
ing, resembling more the topography of the Piedmont plateau than that 
typical of the coastal plain. 

In places near the contact of the coastal plain with the Piedmont 
plateau but extending well within the limits of the plain, the thin veneer 
of loose unconsolidated sands and gravels has been stripped from the sur- 
face, exposing small irregular somewhat elongated areas of the crystalline 
rocks. Many of these areas are composed either in whole or in part of 
granites of good quality. This stripping of the coastal plain sedi- 
ments from the crystallines has taken place mostly along the courses of 
the larger and principal streams. In such areas the granitic rocks are 
usually exposed in ledge and boulder form, and as flat surface masses back 
from the stream a short distance on the two sides. 

The principal granite areas are found in Wilson, Edgecombe, and Nash 
counties to the east of Raleigh, and in Anson and Richmond counties be- 
tween Rockingham and Wadesboro, near the South Carolina line. In 
each of these counties small openings have been made in the granites and 
some of the rock has been quarried for local use. None of the openings, 
however, are sufficiently large to be called quarries and no systematic work 
has yet been undertaken, though the granite is of good quality ; is readily 
accessible and can be easily worked. 

GENERAL FIELD RELATIONS OF THE CRYSTALLINE ROCKS. 

Schists, gneisses, and granites compose the rocks of the crystalline in- 
liers exposed within the western limits of the coastal plain. They mark 
parts of the eastward extension of the Piedmont plateau crystallines 
beneath the coastal plain sediments. A part at least of the schists and 
gneisses are the metamorphosed equivalents of original igneous masses 
and they include both acid and basic types. The basic types carry more 
or less chlorite, hornblende, and epidote which impart a characteristic 

8 Holmes, J. A., Bulletin No. 8, N. C. Geol. Survey, 1899, pp. 19-23. 



THE VARIETIES OF BUILDING STONES. 15 

green color to the rock and it would be properly designated a greenstone- 
schist. Where best exposed such rocks strongly suggest derivation from 
an altered basic igneous rock, probably diorite or diabase. Perhaps the 
best exposures, though considerably weathered, are found in Richmond 
County in and around Rockingham, the county-seat. Partially weathered 
outcrops of the rock are exposed in the street across from the station at 
Rockingham. 

The granites are massive biotite rocks varying from fine even-granular 
to coarse porphyritic in texture and from gray to pink in color. Jointing 
is usually well developed in the granites intersecting the rock in three 
general directions, namely, northwest, northeast, and north-south. The 
granites are younger than the schists and gneisses into which they have 
been intruded, as evidenced by the nature of the few contacts in the par- 
tial decay of the rocks and by their massive structure as contrasted with 
the completely schistose structure of the surrounding rocks. 

Very many dikes of basic composition, largely diabase, penetrate the 
crystalline rocks of the various areas in the coastal plain. The dikes 
vary from 10 to 140 feet in width and they strike in two principal direc- 
tions, northwest and north-south, with most of them cutting in the 
northwest quadrant. They are younger in age than the Newark sand- 
stone which they cut and are older than the coastal plain formations 
which would indicate middle or late Mesozoic age. Petrographic descrip- 
tion of the rocks is given below under the description of the individual 
areas, which are taken up by counties. 

ANSON AND RICHMOND COUNTIES. 

THE WADESBORO-ROCKINGHAM GRANITE AREA. 

The Wadesboro-Rockingham granite area has an east-west extension of 
approximately 14 miles, located partly in Richmond and partly in 
Anson counties. The easternmost outcrops of the granite are exposed 
about 2 miles west of Rockingham, along the Steele cotton mill road, 
only a short distance south of the Seaboard Air Line Railway. It is 
traced westward from this point for a distance of about 14 miles or 
approximately 3 miles east of Wadesboro. East about one mile from 
the western exposure of the granite, the Triassic sandstones first appear 
overlying unconformably the crystalline schists. The intervening area 
between the granite and the sandstone is composed of crystalline schists 
of variable mineral composition ranging from micaceous to quartz schists 
which pass westward beneath the standstones. Most of the area between 
Rockingham and the first outcrops of the granite to the west, is covered 



16 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

by the coastal plain sands, affording but slight evidence of the nature of 
the underlying crystalline rocks in contact on the east side with the 
granite. In and about the town of Eockingham the principal outcrops 
are of greenstone-schist, always much crushed and fractured and thinly 
schistose. No fresh material could be obtained of the rock but the 
weathered outcrops strongly indicate derivation from an original basic 
igneous rock. The schists both to the east and west of the granite mass 
must be regarded as older in age than the granite and forming the country 
rock into which the granite was intruded. 

The northern part of the area is crossed by the main line of the Sea- 
board Air Line Eailway in an east-west direction and it is again crossed 
in a north-south direction by the Pee dee Eiver, which forms the dividing 
line between Eichmond and Anson counties. The largest part of the 
area, however, extends southward from the railroad and west from the 
Peedee Eiver. Irrqgular patches and stretches of the coastal plain sands 
cover the granite over many of its parts. Outcrops of the hard and firm, 
fairly fresh granite are rather numerous, largely in the nature of huge 
boulders, ledges, and flat-surface masses, the latter containing several 
acres of surface in the largest exposures. Exposures of the granite in 
both the weathered and the fresh condition are seen to advantage in the 
cuts at many points along the Seaboard Air Line Eailway. 

Immense boulder and ledge exposures of the granite occur 2-J to 
3 miles west of Eockingham along the Steele cotton mill road at 
Spring Branch near the picnic grounds. Extensive exposures of the 
same nature occur over the hill-slope and in the railroad cut at the foot 
of the hill where Hitchcock's Creek is crossed by the railroad. The 
granite is extensively exposed in the vicinity of Lilesville, 5 miles east 
of Wadesboro, in the cuts along the Seaboard Air Line Eailway, and back 
from the railroad as flat-surface masses and large boulders. About one- 
quarter of a mile north of Lilesville flat-surface masses of the granite are 
exposed over a considerable area on the two sides of a small stream. 
Approximately 2-J miles south of Wadesboro is a flat-surface 
exposure of the granite of more than an acre in extent, locally known as 
" flat-rock." The exposure has a gentle southward slope of about five 
degrees which ends abruptly in a face of 8 to 10 feet. 

In all the outcrops observed the rock is fairly uniform in both color 
and texture. It is coarse-textured, porphvritic bietite granite of a de- 
cided pinkish-gray color, tinged a delicate yellowish-green color which 
becomes stronger in some places than in others. The rock derives its gray 
color from the presence of black biotite, while the pink and yellow tints 
are imparted by the abundance of feldspars of those shades. Over most 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE IV 




A. WEATHERED GRANITE IN RAILROAD CUT WEST OK LILESVILLE, ANSON COUNTY. 




B. DECOMPOSED DIABASE DIKE IN PORPHYRITIC GRANITE. LILESVILLE, ANSON COUNTY. 



North Carolina State 
Raleigh 



Library 



THE VARIETIES OF BUILDING STONES. 17 

of the area the rock has a peculiar resinous lustre imparted by its 
feldspathic constituent. 

The groundmass of the rock is a medium coarse-grained dark gray 
even-granular granite, containing over most of the area a somewhat 
increased amount of biotite. In several exposures the biotite is less 
abundant and the rock is correspondingly lighter in color with the resin- 
ous-like lustre more emphasized. This is especially noticeable in the 
exposures of the granite in the Seaboard Air Line Eailway cut one to one 
and a half miles west of Lilesville. In this exposure the biotite has quite 
a different occurrence and distribution in the rock from that of any other 
exposure examined in the Eockingham-Wadesboro area. Here the mica 
is in small hexagonal plates, deep black in color and highly lustrous with 
the interspaces filled by the lighter colored constituents larger than in the 
rock elsewhere exposed. The boundaries between the biotite are sharp 
and clearly defined and the crystals are distributed through the ground- 
mass of the rock as single individuals and aggregates occupying distinct 
areas. Elsewhere over the area the biotite occurs as irregular shreds and 
plates usually crowded close together and freely distributed through the 
groundmass resulting in a darker color imparted to the granite. In 
places biotite appears to be the principal constituent composing the 
groundmass (see Pis. IV, A, and V, A). 

The phenocrysts are composed of potash feldspar in which the two 
cleavages have pronounced development. They are decidedly pink in 
color sometimes of a yellowish tone when the resinous-like lustre is quite 
apparent. The yellowish caste of the feldspar, so pronounced in the 
granite exposed in the railroad, cut to the west of Lilesville, seems appar- 
ently due to surface alteration. Twinning after the Carlsbad law is 
nearly invariably developed in the feldspar phenocrysts. They are 
more or less idiomorphic, flat-tabular and much elongated in form, al- 
though irregular rounded allotriomorphic outlines are quite common 
among them. In size they range from more than one inch in length and 
proportionately broad down to the size of the groundmass constituent into 
which they sometimes grade. Inclusions of the groundmass biotite are 
more or less conspicuous in the phenocrysts. The proportion of pheno- 
crysts to groundmass is somewhat variable but a probable average ratio as 
nearly as could be estimated is about 1 to 3. 

At a small opening recently made in exposures of the porphyritic 
granite on the Steele's mill road where crossed by Spring Branch, two 
and a half miles west of Eockingham, black segregated areas or bunches 
of biotite are rather numerously distributed through the granite. They 
range in size from small roughly rounded oval-shaped areas to much 



18 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

elongated ones in which the length is several times that of the width. 
They are more or less irregular in outline and the largest ones will 
measure 8 to 12 inches in length and 2 to 4 inches wide. The 
color is black and the segregations are composed almost entirely of fine 
shreds of biotite much smaller than that of the groundmass of the granite 
proper. Occasional phenocrysts of pink feldspar of irregular outline are 
distributed through them, which is apparently the only light colored 
mineral visible to the unaided eye. The black areas are exceedingly fine- 
grained in texture. In other outcrops of the granite, segregation areas 
of biotite are only occasionally observed. 6 

In the opening 3 miles west of Eockingham where Hitchcock Creek 
is crossed by the Seaboard Air Line Kailway, pyrite is very sparingly dis- 
seminated through the granite, common alike to both phenocryst and 
groundmass. At no other point, however, is pyrite disseminated through 
the rock approaching anything like a sufficient quantity to prove harmful 
to the granite when used in exterior work. 

Weathering. — In very many places over the area the granite is deeply 
decayed but it is easily traced by the rather thickly strewn, partially de- 
cayed, white opaque, kaolinized and broken fragments of the large feld- 
spar phenocrysts, and the large quartz grains of the groundmass, over the 
surface. The most favorable sections for studying the granite weathering 
are in the vicinity of Lilesville, in the cuts along the Seaboard Air Line 
Eailway, 1 to 2 miles east and west of the Station. In each one of the 
cuts examined the granite indicates an advanced stage of decay, whose 
depth will vary from several feet to 15 and 20 feet. In some instances 
the rock is completely broken down into a deep ferruginous siliceous clay 
in which neither feldspar nor mica particles are visible as such to the un- 
aided eye. Usually the decayed product will vary in color from a light 
rusty yellowish-brown, due to the partial discoloration from the iron 
oxide, to that of approximately the same color of the fresh granite in 
which the principal minerals are all distinguishable but have lost their 
lustre, and the rock readily crumbles or falls to pieces under gentle 
pressure (see PI. IV, A and B, and PI. V, A). 

Several feet below the surface, the decay has progressed mainly along 
the jointing and invisible fractures in the rock, shown by large and small 
masses of the nearly fresh granite embedded in the decay but occupying 
their original positions in the decay as in the fresh granites (PL IV, A). 

Openings. — Notwithstanding the unlimited quantity of this granite and 

6 For a description of similar areas in the Maine granites see a paper by Dr. Geo. P. 
Merrill, entitled "On The Black Nodules or So-Called Inclusions in the Maine Gran- 
ites," Proceedings U. S. National Museum, 1886, pp. 137-141. 



THE VARIETIES OF BUILDING STONES. 19 

its ready accessibility, only a little stone has been quarried np to the pres- 
ent time. Less than a half dozen small openings have been made in the 
granite over the entire area. These have been made at different places, 
namely, 2-J miles west of Kockingham, the county-seat of Richmond 
County, at the crossing of Spring Branch by the Steele mill road, where 
a recent opening has been made in a large boulder and ledge outcrop of 
the porphyritic granite; 3 to 3-| miles west of Eockingham along the 
Seaboard Air Line Railway where crossed by Hitchcock Creek, from 
which some of the stone was quarried and used in the piers of the railroad 
bridge across Pedee River; at several points f to If miles west of Liles- 
ville, along the south side of the railroad. 

Almost any of the large outcrops of the granite offer good quarry sites. 
The rock is quite accessible. It is susceptible of a fine polish and in the 
deeper pink and yellowish shades of the granite, it should prove a desir- 
able stone for interior work. A block of this granite was obtained from 
the opening 2-J miles west of Rockingham at Spring Branch for exhibition 
at the St. Louis Exposition. 

Jointing. — Jointed structure is usually well developed in the exposures 
of the porphyritic granite over the area, but in none of them has it been 
observed to cut the rock at intervals too close to prevent the quarrying of 
dimension stone. Measurements of the joints have been made in expos- 
ures of the granite at the following places which may be taken as repre- 
sentative directions of the joints for the entire area ; one-quarter of a mile 
north of Lilesville, extensive flat-surface exposures of the granite showed 
three sets of joint-planes striking N". 70° E., NT. 20° W., and a less con- 
spicuous set, 1ST.-S. At Flat rock, a flat surface exposure of the granite, 
2-J miles south of Wadesboro, two sets of joint-planes intersect the granite 
striking K 30° E., and K 60° W. 

The jointed structure of the porphyritic granite is well shown in Plate 
V, fig. A, which also illustrates the weathering of the rock along the 
breakage lines. 

Microscopical Examination. — A thin section cut from the groundmass 
of a specimen of porphyritic granite collected from the opening at Spring 
Branch, 3 miles west of Rockingham, showed, under the microscope, 
a medium-grained biotite granite, composed of an aggregate of quartz and 
feldspar with considerable biotite. Potash feldspars with nearly equal 
or greater proportion of plagioclase make up the feldspathic constituent, 
which shows some alteration and contains the usual microscopic inclu- 
sions. Biotite has the same occurrence, color and absorption and displays 
the usual alteration and by-products. A few scattered grains of magne- 
tite are distributed through the section with no injurious minerals noted. 



20 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

A thin section of similar rock exposed in the Seaboard Air Line 
Railway cut, one mile west of Lilesville, is identical under the micro- 
scope with that described above, except that no microcline occurs in the 
rock near Lilesville. 

DIKES OF BASIC INTRUSIVE ROCKS IN THE ROCKINGHAM- WADESBORO 
CRYSTALLINE AREA. 

From Eockingham to Wadesboro the crystalline area is penetrated by 
dikes of basic igneous rocks which vary in width from a few feet to sev- 
eral hundred feet. Within the western limits of the town of Rockingham 
at the Great Falls cotton mill is a much crushed and otherwise altered 
though massive diabase dike striking N.-S. and more than 100 feet wide. 
The rock is dense and hard and considerably altered, containing large 
areas of quartz and much epidote. It is of a pronounced greenish color 
imparted by the alteration products and would be properly designated a 
greenstone. In the construction of the mill-dam it was necessary to do 
a vast amount of blasting of the rock thereby affording a large and excel- 
lent exposure of the dike. 

Between 2 and 2J miles west of Rockingham on the Steele 
mill road the porphyritic granite is penetrated by a dike of fine- 
grained nearly black diabase 25 or more feet wide and striking north- 
west. Three and a half miles west of the same town, one quarter of a 
mile north of the Steele cotton mills and on the north side of the rail- 
road, the granite is penetrated by a dike of dense, medium-grained, black 
norite, 300 feet wide and striking N.-S. A small opening was made in 
the dike at this locality some years ago and a few stones were obtained for 
use in the piers of the railroad bridge across Peedee River. Results of 
tests of this rock for road material are given on p. 266. 

In a cut along the Seaboard Air Line Railway, 1J miles east of Liles- 
ville, a dike of medium-grained diabase, nearly black in color, 140 feet 
wide, striking N". 20° W., cuts the porphyritic granite. None of the 
fresh granite is exposed in the railroad cut at this point but it can 
easily be identified by its characteristic decay (PL IV, B). West of 
this dike about \ of a mile and near the 129 mile-post on the railroad is 
a second dike of similar character penetrating the granite, and is 25 feet 
across. 

There are two parallel diabase dikes near together and not exceeding 
10 feet in width and striking ¥. 20° W. and cutting the granite, 3 miles 
east of Wadesboro, on the Lilesville-Wadesboro Road and three-quarters 
of a mile south of the railroad. About one-quarter of a mile further 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE V 




A. RESIDUAL DECAY DERIVED FROM THE WEATHERING OF PORPHYRITIC GRANITE, I MILE WEST OF 
LILESVILLE. ANSON COUNTY. 




B. GRANITE DIKE PENETRATING DECAYED ROCK, I MILE WEST OF WOODLEAF, ROWAN COUNTY. 



THE VARIETIES OE BUILDING STONES. 21 

west on the same road, a similar dike but wider and striking N. 20° W., 
is exposed in front of Mrs. Bennett's residence. 

From this point west to Wadesboro and beyond for some miles, dikes 
of diabase become more numerous, penetrating the Triassic sandstones. 
Not less than 40 of these dikes have been observed within these limits 
on which careful observations were made and specimens collected from 
the more important ones. The variation in strike is from 1ST. 10°-35° 
W., with the same variation in width noted as those penetrating the 
crystalline rocks described above and to the east of the sandstone area. 
The texture ranges from medium- to fine-grained and they are uniformly 
hard and dense black rocks. 

The dikes mentioned above comprise only some of the more important 
ones cutting the crystalline rocks in Richmond and Anson counties. 
With possibly one or two exceptions, the dikes penetrating the area are of 
late Triassic age, as they are found intersecting both the crystallines and 
the sandstones, whose age in the latter case is Triassic. 

WILSON COUNTY. 

Introductory Statement. — Small areas of crystalline rocks are exposed 
at only a few places in Wilson County. With these few exceptions, the 
entire County is covered by the sediments of the coastal plain formation. 
Only two of the crystalline areas are known to contain workable granites, 
namely, 3 miles south of Wilson, the county-seat, at the crossing of 
Contentnea Creek by the Atlantic Coast Line Railway, and extending 
up stream from this point for a distance of several miles; and 2J to 3 
miles north of Elm City (Toisnot), a station on the Wilmington and 
Weldon Railroad. 

THE CONTENTNEA CREEK GRANITE AREA. 

To the south of Wilson, about 3 miles, beginning at the Atlantic 
Coast Line Railway crossing over Contentnea Creek, granite is exposed 
for a distance of several miles up stream on the two sides of the creek. 
The granite is exposed as immense boulders along the stream and as flat- 
surface masses a short distance back from the creek on either side. Ex- 
posures of the granite occur at and near Wiggings mill on Contentnea 
Creek, 1 to 1-| miles west of the railroad crossing, and they continue for 
some distance along the stream both above and below the mill. 

The granite is a uniformly coarse-grained rock of a pinkish-red color 
imparted by the predominant feldspathic constituent of the same color. 
It has a marked porphyritic tendency. The feldspars are in considerable 



22 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

excess over the other minerals, and the characterizing accessory biotite 
is only sparingly present, usually not in large enough amount to impart 
any distinctive color to the rock. The feldspathic constituent in this 
granite has been estimated by the road material laboratory in Washing- 
ton, D. C, to amount to 82 per cent, proportioned as follows: Ortho- 
clase, 50 per cent; plagioclase (albite), 32 per cent. Cleavage in the 
feldspars is typically developed and Carlsbad twinning is the rule. The 
larger feldspar individuals will measure 1-J to 2 inches long by J to 
\ inch wide. They are usually flat-tabular in outline, grading into 
stout nearly equidimensional forms, and are prevailingly pinkish-red in 
color and highly lustrous. 

Quartz is next abundant to feldspar and is of the slightly smoky, dark 
vitreous variety, distributed as large anhedra through the rock, which 
contrast sharply with the feldspar. Biotite is in very small shreds and 
plates, and is only sparingly distributed through the rock. 

Microscopical Examination. — Under the microscope, the thin sections 
show the Wilson granite to be composed essentially of feldspar and quartz, 
with the former in much the largest amount. These two' make up at 
least 90 per cent of the rock. Plagioclase nearly equals in amount the 
potash feldspar, which consists mostly of orthoclase though some micro- 
cline occurs. Plagioclase is in very large laths, finely striated and cor- 
responds in physical properties to albite. The feldspars are extensively 
altered to kaolin and muscovite, not a single entirely fresh individual 
being found in the slides examined. Quartz is in very large grains 
interlocking with the feldspar and will probably not exceed 15 per cent 
of the entire rock. Biotite, the chief characterizing accessory, is only 
sparingly present, and is largely altered to chlorite. Occasional small 
grains of iron oxide and a few inclusions of prismatic apatite complete 
the list of accessories. 

The weathered surfaces of the granite exposed near the mill on Con- 
tentnea Creek are light in color with a very faint pinkish tone. The 
feldspars are dull and opaque and have lost much of their decided pink 
color so characteristic of the same constituent in the fresh granite. 

A small opening was made some years ago at the Contentnea Creek- 
Wilmington and Weldon Railroad crossing, in a flat-surface outcrop of 
the granite. The opening is located so close to the railroad tracks that 
the quarried blocks could be swung by derricks directly onto the cars 
from the opening. Very little sap (partially decayed granite) is found 
on the granite at this exposure but fresh rock begins at the surface. 
Some of the stone was used by the railroad company in the bridge piers 
at Contentnea Creek crossing; and also in the walls at the entrance to 



THE VARIETIES OF BUILDING STONES. 23 

Atlantic Coast Line Eailway office, building at Wilmington, North Caro- 
lina. Good specimens were also secured from this opening for the col- 
lection of building stones in the State Museum at Raleigh. The open- 
ing will probably average 12 feet in depth, is roughly circular in outline 
and of less than a quarter of an acre in extent. It is not located many 
feet above the stream level. 

Three sets of joints break the rock into polygonal blocks of various 
dimensions, striking about N.-S., N. 70° W., and N. 50° E., having 
apparently about equal development. No seams, veins nor segregations 
cut the granite and no deleterious minerals that would cause discolora- 
tion on exposure, such as pyrite, are present. The granite splits readily 
and it takes a fine polish as indicated by the dressed cubes in the State 
Museum at Raleigh. Stone of moderate size can be quarried and the 
granite may prove a desirable one, especially for monumental and orna- 
mental stock. Results of tests of this rock for road material are given 
on p. 266. 

THE ELM CITT GRANITE AREA. 

This area includes some 15 to 20 acres of boulder outcrops of 
a light gray granite, located just across the Edgecombe County line and 
in the extreme northern part of Wilson County, about one-quarter of a 
mile east of the Wilmington and Weldon Railroad and 3 miles north 
of Elm City (Toisnot). One opening has been made which is reported 
to have been first worked prior to the Civil War. It covers approximately 
| to f of an acre in extent and is worked to an average depth of 30 feet. 
The decay at the top of the opening will average about 6 to 8 feet in 
depth, deeper than this in some places and considerably less in others. 
Near the surface the decay consists of a red gritty clay passing at a slight 
depth into lighter shades and finally grading into the hard firm granite 
at about the depth mentioned above. 

Work was resumed in April, 1903, to supply stone on contract for 
macadamizing the streets in the town of Wilson. In June, 1903, stone 
was being quarried for a similar purpose to be used in the town of Golds- 
boro. It is said to have been previously used somewhat extensively in 
railroad construction and as curbing and building stone in Wilmington, 
and also in the foundations of the Post Office building in Raleigh. Re- 
sults of tests of this rock for road material are given on p. 266. 

The granite is light gray in color with a faint pinkish tone imparted 
by the feldspar. It is medium coarse-grained in texture, firm and com- 
pact and exceedingly hard. Biotite is in minute shreds very much 
smaller than the feldspar and quartz individuals and shows a marked ten- 



24 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

dency at times to form segregations. It is present in small amount, but 
it is in quantity considerably over that of the Contentnea Creek red gran- 
ite in the same County. 

Two sets of joints striking N; 80° W., and N. 40° E., cut the granite. 
A rather pronounced schistose structure is noted in the granite over the 
quarry floor, striking about north and south. A very fine-grained slightly 
greenish black dike of amphibolite containing much disseminated pyrite, 
penetrates the granite in the quarry in an approximately northwest-south- 
east direction. On the west side of the quarry the dike has a width of 
about 4 feet but on the east side it thickens up to a cross section 
measuring nearly 20 feet. It is finely laminated and closely jointed, 
blocking out in small rhomboidal sections and is penetrated in all direc- 
tions by ramifying veinlets of white feldspar of scarcely more than knife- 
edge thickness. The pyrite grains are mashed and squeezed in the direc- 
tion of the lamination. Quartz veins also cut the granite in a general 
north-south strike. Two of the veins observed on the west side of the 
quarry and near the dike are about 12 inches wide and interbandecl 
or wrapped with films of hornblende. 

Microscopical Examination. — Miscroscopic study shows the rock to be 
a biotite granite through which are scattered occasional partially idio- 
morphic crystals of compact hornblende. Feldspar preponderates and 
is composed of the potash varieties with much striated acid plagioclase 
whose extinction angles measured against the twinning lamellae corres- 
pond to a feldspar of the composition Ab 12 An ± . The feldspars are clouded 
from slight alteration into kaolin and muscovite. Micropoikilitic struc- 
ture is well developed in some of the larger individuals of the potash 
feldspar, the inclusions consisting of large microscopic grains of quartz 
and striated plagioclase without apparent orientation. Quartz forms 
distinct areas of an interlocking mosaic of smaller grains than the feld- 
spar, through which are scattered occasional feldspar grains and biotite. 
Biotite is less abundant, forming small plates of brown color and strongly 
pleochroic, bleached to green on alteration, and is further altered to 
chlorite. In one slide of the granite several small crystals of compact 
hornblende with good cleavage development were noted. The principal 
accessories include zircon, apatite, a little titanite, and ilmenite. 

Microscopically, the thin sections of the dike penetrating the granite 
in the quarry indicate a very fine-grained amphibolite-schist, in which 
the arrangement into roughly alternating bands of dark green hornblende 
and quartz is shown. In the hand specimen the fine schistose structure 
is pronounced and the rock appears to be made up entirely of hornblende 
with much scattered pyrite. 



THE VARIETIES OF BUILDING STONES. 25 

Hornblende, in irregular elongated shreds, is the predominant mineral. 
It is strongly pleochroic from deep bine-green to deep brown, only occa- 
sional grains of which indicate traces of the two cleavages. Associated 
with the hornblende is much epidote in small granules forming aggre- 
gates. Only one or two shreds of feldspar were noted in the sections. 
Quartz is next abundant to hornblende. It shows strain shadows re- 
sulting from mechanical stresses in the rock and it contains somewhat 
numerous inclusions of small stout prisms of apatite. 

The structural relations of -the rocks in the quarry clearly indicate a 
greater age for the dike than for those dikes of basic rocks penetrating 
the rocks in the Rockingham-Wadesboro area, for the same period of 
metamorphism which affected the granite likewise induced the schistose 
structure in the basic dike rock. 

The joint-plane surfaces are slickensided and coated with a thin 
veneer of a dark green to yellowish green micaceous mineral, probably 
damourite. Much of a yellowish-green mineral, probably epidote, is 
observed in the granite in places, an alteration product derived from the 
biotite. 

The working qualities of the granite are not good, which coupled with 
the rather close jointing and the numerous seams which cut it, render 
the granite unsuited for general constructional purposes. Dimension 
stone could only be obtained by careful selection, but the cost of quarry- 
ing to supply only this demand would be entirely too great as the waste 
would be almost excessive. The rock admirably serves the purpose for 
which it is quarried at present. Eesults of tests of this rock for road 
material are given on p. 266. 

The usual method of steam drilling and blasting is employed in quarry- 
ing the stone. During the summer of 1903 an average force of twenty 
men were employed in getting out the stone for macadamizing the streets 
of Goldsboro. 

EDGECOMBE AND NASH COUNTIES. 

Description of the Granite. — Beginning about one mile north of Rocky 
Mount in Edgecombe County, boulder outcrops and small flat-surface 
exposures of granite are traced along Tar River for some distance west- 
ward into Nash County. The granite is traced on both sides of the 
river and is exposed in places in the bed of the river. 

Extending in a general west course from Rocky Mount to Springhope 
in Nash County, a distance of about 20 miles, and thence in a north- 
south course along the Nash-Franklin County line into Halifax County, 
is a large but irregular area of crystalline rocks consisting mostly of 



26 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

chloritic schists, gneiss, and diorite. Abundant quartz veinlets intersect 
the rocks of this area conforming in part to the schistosity of the en- 
closing rocks and in part cutting across the schistosity. For many years 
it has been one of the gold-producing areas in the State. 7 

No contacts between the schistose rocks and the granite were noted but 
it is probable that the granite postdates the schists inasmuch as the latter 
suggest derivation in part at least from original igneous masses. 

At the cotton mill on Tar Eiver, one mile north of Eocky Mount, 
several small openings were made in the granite some years ago to obtain 
stone for local use. Four sets of joints cut the rock, breaking it into 
blocks of various dimensions. The more prominent ones of these sets 
strike about N.-S., and NE.-SW. The two less conspicuous sets strike 
1ST. 30° W., and N". 80° W. These joints cut the granite at distances 
varying only a few inches apart in some places to many feet apart in 
other places. 

Pegmatite veins, varying from a fraction of one inch to more than 6 
inches in width, and composed of pink feldspar and quartz with a very 
small amount of biotite, intersect the granite. All gradations between 
those veins containing mostly feldspar to those containing mostly quartz 
are noted. In some of them the quartz forms a narrow central band is. 
the feldspar of the vein. Some of the veins are banded with a fine- 
grained granite of the same • mineral composition as the main granite 
mass. A part of these veins are true veins of segregation since they 
pinch out in the granite mass and the granite can be traced entirely 
around them. Except in a few places perhaps, the joints or veins do not 
interfere with stone of large size being quarried. 

Several pieces of diabase were scattered over the surface on the north 
side of the river immediately adjacent to the granite exposures. These 
were not in place, but they evidently indicate a dike of the basic rock cut- 
ting the granite nearby. 

The granite is a medium-grained, gray, biotite rock, the feldspars of 
which have a decided pinkish tone. It differs from the granite quarried 
3 miles north of Elm City in the southern part of the County in 
being massive and not schistose in 'structure. It is apparently of good 
quality and should prove a satisfactory stone for general purposes. Most 
of the exposures are sufficiently large and with sufficient elevation above 
the water level of the river to admit of workable quarries being opened. 

Microscopical Examination. — A thin section of the rock from the 
openings made on Tar Eiver near the cotton mill, one mile north of 
Eocky Mount shows, under the microscope, a medium-textured biotite 

7 Nitze, H. B. C, N. C. Geol. Survey, Bulletin No. 3, 1896, p. 24, et seq. 



THE VARIETIES OF BUILDING STONES. 27 

granite, composed of a closely interlocked aggregate of feldspar, quartz, 
and biotite. Orthoclase and microcline have about equal distribution 
through the section with but little plagioclase indicated. Much of the 
quartz occupies distinct areas, forming a fine-grained mosaic between the 
larger feldspars. Quartz-feldspar areas in the form of micrographic 
structure are freely distributed through the section. Biotite occurs in 
the form of irregular shreds and plates of deep brown color and strong 
pleochroism, containing inclusions and partly altered to chlorite and a 
little epidote. A few scattered grains of black iron oxide and inclusions 
of prismatic apatite and zircon complete the list of minerals in the rock. 

RESUME OF THE GRANITES OF THE COASTAL PLAIN REGION. 

Briefly summing up some of the principal points developed in the fore- 
going description of the individual granite areas of the coastal plain 
region, it is noted first, that the workable granites are limited to irregular 
small areas exposed well within the limits of the inner western margin 
of the coastal plain, by stripping in places of the loose materials be- 
longing to this horizon. The areas capable of producing workable 
granite are exposed in Anson and Eichmond counties along the South 
Carolina line, and in Wilson, Edgecombe, and Nash counties to the east 
of Ealeigh. 

These areas either lie close to or are crossed by the principal lines of 
railroad in the eastern portion of the State, rendering them easily acces- 
sible and providing ample facilities for transportation of the stone. The 
outcrops are usually large and are so located as to offer advantageous 
quarry sites. 

The granites of the coastal plain region show considerable range in 
yarktion of color and texture, from light gray to pink with a very pleas- 
ing mixed yellowish and pink appearance in some places in the Wadesboro- 
Eockingham porphyritic granite area. Variation in texture is from 
coarse and medium-fine even-granular to coarse porphyritic. 

In composition they are all biotite granites, the Elm City area in 
Wilson and Edgecombe counties containing some additional hornblende. 
The accessory biotite is but scantily developed in the Contentnea Creek 
pink granite in Wilson County, a circumstance which taken in connec- 
tion with the small size of the biotite shreds, exercises no effect on the 
color of the rock. Quartz also seems less abundant in the Wilson pink 
granite than in the other granite areas of the coastal plain. The most 
noteworthy microscopical feature of the coastal plain granites is the 
rather large proportion of acid plagioclase in the rock of some of the 
areas, and it is present in all. 



28 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

THE GKANITES OF THE PIEDMONT PLATEAU KEGION. 

GENERAL GEOGRAPHIC AND GEOLOGIC DESCRIPTION. 

The Piedmont plateau region in North Carolina, lying between the 
coastal plain and the Appalachian Mountains, has an- average width in 
an east-west direction of approximately 125 miles, and an approximate 
area of 21,000 square miles. 8 

The principal topographic feature is the rather gently rolling surface 
which forms the plateau upland. Its surface is not entirely smooth but 
it is cut into deep and narrow channels by the streams which flow across 
it. This surface was reduced to its present moderate relief by the action of 
sub-aerial agents. It has a general gentle eastward slope from an average 
elevation at the western edge of from about 1,200 to 1,500 feet to 250 to 
400 feet along the eastern edge where the plateau rocks pass beneath the 
coastal plain sediments. Eesidual masses (unreduced areas or monad- 
nocks) such as South and Brushy mountains and numerous others, both 
low and high, rise above the general level of the upland surface. 

Examination of the accompanying map, PI. Ill, shows the plateau to be 
composed of a number of geologic belts which are approximately parallel 
to e'ach other and cross the State in a general northeast-southwest direc- 
tion. As a rule, these belts are composed of unlike rocks of different 
ages. According to Professor Kerr * they are, named in order from east 
to west, as follows : 

(1) A narrow irregular and partially disconnected belt of sandstones 
and shales which extends northeastward from Wadesboro nearly across 
the State. This series of sedimentaries is penetrated by numerous dikes 
of diabase whose directions coincide with the jointing of the sandstone, 
the whole referred to Triassic age and known as the Deep Eiver area. 

(2) A continuous but wider belt which extends entirely across the 
State and composed of metamorphic slates and schists, including large 
areas of both acid and basic volcanic rocks, the whole referred to prob- 
able pre-Cambrian age. Outcrops of granite are exposed at several 
points within the limits of the belt but as yet none of the stone has been 
quarried. 

(3) A central belt of granite, granite-gneiss, and more basic igneous 
rocks of which diorite forms perhaps the largest areas. The belt is 
designated as lower Lauren tian (Archaean) in age by Professor Kerr. A 
smaller area of similar rocks and age, designated in this report as the 
Northeastern Carolina Granite Belt, occupies the extreme northeastern 

8 Holmes, J. A., Bulletin No. 8, N. C. Geol. Survey, 1899, pp. 23-25. 

9 Kerr, W. C, Geology of North Carolina, 1875, Vol. I ; and accompanying map. 



THE VARIETIES OF BUILDING STONES. 29 

part of the Piedmont region, immediately to the east and north of the 
northern limits of the belt of Triassic sandstones. 

(4) A very wide belt covering the entire western limits of the Pied- 
mont region, composed principally of gneiss and schist with scattered 
areas of granite and more basic igneous rocks usually in the form of 
dikes. How much of the gneiss belonging to this area is sedimentary 
in origin and how much of it is igneous, it is not yet possible to say. 
That some of the gneisses in this belt, however, are derived from original 
igneous rock-masses does not admit of reasonable doubt, as developed 
Jater in this report in some of the descriptions of the individual areas. 
The predominant rocks of the belt have been referred to by Professor 
Kerr as probably Archaean in age. 

Eecent studies in the different areas of the Piedmont region of North 
Carolina indicates that the older rocks are penetrated by very many dikes 
of basic igneous rocks of different types, a part of which are of undoubted 
Triassic age. Other dikes of the same rock types for reasons elsewhere 
stated in this report can, with much certainty, be referred to an earlier 
period of intrusion than that of the Triassic. 

It is within the limits of the Piedmont plateau region that the great- 
est distribution and development of granites and gneisses of commercial 
importance in North Carolina occur. Considerable variety and abund- 
ance of these are noted. The quality in most places is generally ex- 
cellent; the stone is readily accessible, and, as a rule, it can be easily 
worked. Numerous quarries have been worked from time to time over 
many parts of the Plateau region, and so far as the term is applicable the 
granite industry in the State belongs almost exclusively to this Plateau 
region. 

The granitic rocks of the northeastern area, comprising the counties of 
Wake, Franklin, Vance, Granville, and Warren ; those of the metamorphic 
slate-schist and volcanic belt; those of the central granite belt, including 
Mecklenburg, Gaston, Cabarrus, Iredell, Eowan, Davidson, Davie, For- 
syth, Guilford, and Alamance counties; and those of the western gneiss 
belt comprising the counties of Surry, Wilkes, Alleghany, Alexander, and 
Cleveland, are described below in detail under the four geologic divisions 
made of the Piedmont region (see maps, Pis. Ill and VI). 

THE NORTHEASTERN CAROLINA GRANITE BELT. 

GENERAL CONSIDERATIONS. 

The position and limits of this belt are shown on the accompanying 
map, Plate VI. Its eastern limits mark the line of contact with the 
coastal plain sediments. On the south the rocks of the area pass be- 
4 



30 BUILDING AND ORNAMENTAL STONES OE NORTEL CAROLINA. 

neath the coastal plain formations along a line drawn in a general north- 
west course from near Smithfield in Johnston County, through Wake 
County to a point about 10 miles west of Ealeigh. It is limited on the 
west by the Triassic sandstones and the so-called metamorphic slate- 
schist-volcanic belt. It extends northward into Virginia. 

The belt includes a whole or a part of Wake, Franklin, Granville, 
Vance and Warren counties. Granites, gneisses and schists of the mica 
type, intersected by dikes of basic igneous eruptives, comprise the 
principal rocks of the area. The granites are, with only a few exceptions, 
more or less schistose in structure. As a rule, however, the schistosity 
is not so completely developed as to render the rock unsuited for most 
uses that the original massive rock might have proved desirable. 

Over all parts of the area the rocks are covered by a heavy mantle of 
residual decay — the result of weathering. Outcrops of the hard and 
firm, nearly fresh granite, are fairly numerous, however, over most of 
the belt. The exposures are mostly in the nature of boulder and ledge 
outcrops along the stream courses and as flat-surface or slightly doming 
masses away from the streams. 

The principal quarries in the belt are those first opened many years ago 
within the city limits of Ealeigh, from which stone was obtained for the 
State Capitol and other buildings and, for street purposes in the city of 
Ealeigh; and at Greystone and Middleburgh, stations on the Seaboard 
Air Line Eailway, in Vance County. At both Ealeigh and Greystone the 
quarries have been worked at intervals, extending over a long period of 
years and the openings are quite extensive. More recently numerous 
smaller openings have been made in many places over the belt to supply 
a local demand. 

WAKE COUNTY. 

Most of Wake County is underlaid by granitic rocks, usually deeply 
decayed. The fresh rocks where exposed are usually schistose in struc- 
ture, derived in part at least from original massive granites and are true 
granite-gneisses. Large areas of mica-schist compose the principal rock 
in places, especially to the west and northwest of Ealeigh. The principal 
exposures in which openings have been made can be grouped and best 
treated separately under two areas, namely, (a) The Ealeigh Granite 
Area; and (b) The Wyatt-Eolesville Granite Area. 

THE RALEIGH GRANITE AREA. 
THE CITY QTJABEIES. 

Within the eastern limits of the city of Ealeigh, about 1£ miles 
from the State-house, and near the Federal Cemetery, two large 



N. C. GEOLOGICA 



BULLETIN NO. 2. PLATE VI 




30 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

neath the coastal plain formations along a line drawn in a general north- 
west course from near Smithfield in Johnston County, through Wake 
County to a point about 10 miles west of Ealeigh. It is limited on the 
west by the Triassic sandstones and the so-called metamorphic slate- 
schist-volcanic belt. It extends northward into Virginia. 

The belt includes a whole or a part of Wake, Franklin, Granville, 
Vance and Warren counties. Granites, gneisses and schists of the mica 
type, intersected by dikes of basic igneous eruptives, comprise the 
principal rocks of the area. The granites are, with only a few exceptions, 
more or less schistose in structure. As a rule, however, the schistosity 
is not so completely developed as to render the rock unsuited for most 
uses that the original massive rock might have proved desirable. 

Over all parts of the area the rocks are covered by a heavy mantle of 
residual decay — the result of weathering. Outcrops of the hard and 
firm, nearly fresh granite, are fairly numerous, however, over most of 
the belt. The exposures are mostly in the nature of boulder and ledge 
outcrops along the stream courses and as flat-surface or slightly doming 
masses away from the streams. 

The principal quarries in the belt are those first opened many years ago 
within the city limits of Ealeigh, from which stone was obtained for the 
State Capitol and other buildings and, for street purposes in the city of 
Ealeigh; and at Greystone and Middleburgh, stations on the Seaboard 
Air Line Eailway, in Vance County. At both Ealeigh and Greystone the 
quarries have been worked at intervals, extending over a long period of 
years and the openings are quite extensive. More recently numerous 
smaller openings have been made in many places over the belt to supply 
a local demand. 

WAKE COUNTY. 

Most of Wake County is underlaid by granitic rocks, usually deeply 
decayed. The fresh rocks where exposed are usually schistose in struc- 
ture, derived in part at least from original massive granites and are true 
granite-gneisses. Large areas of mica-schist compose the principal rock 
in places, especially to the west and northwest of Ealeigh. The principal 
exposures in which openings have been made can be grouped and best 
treated separately under two areas, namely, (a) The Ealeigh Granite 
Area; and (b) The Wyatt-Eolesville Granite Area. 

THE RALEIGH GRANITE AREA. 
THE CITY QUARRIES. 

Within the eastern limits of the city of Ealeigh, about 1J miles 
from the State-house, and near the Federal Cemetery, two large 



I GEO] OGI< M Sl'KVEV 



BULLETIN NO. 2. PLATE 



7— -——--- v>- -/ ■-7'--7"^-pr7"T 




THE VARIETIES OF BUILDING STONES. 31 

openings from which much stone has been quarried, were first made more 
than seventy years ago. The records are incomplete and do not afford 
the exact date of the opening of these quarries. Some stone was quarried 
prior to 1833 for local use, and from 1833 to 1836 systematic quarrying 
was done to obtain stone for building the State-house. Work has been 
resumed at intervals from that time to the present to obtain stone for 
various purposes, chiefly for paving-blocks and macadam for the streets 
of Ealeigh. During the summer of 1903 a small force was working the 
larger opening, quarrying blocks for street paving. Two Gates crushers 
were in operation pulverizing and grading the quarry-waste for road 
metal and for railroad ballast. 

Two openings have been made on the opposite sides (north and south) 
of the street, with average dimensions as follows: the north opening, 
which is the largest and principal one, 850 feet long in a north-south 
direction, 75 feet wide, and worked to a depth of 30 to 35 feet. The 
south and smaller opening is 330 feet long in a north-south direction, 75 
feet wide, and 25 feet deep. As indicated by the size of these openings, 
the amount of stone quarried from them is very large. 

An average depth of about 3 feet of deep red clay derived from 
the decomposition of the granite is exposed at the top of the openings. 
The depth of residual clay is greater than 3 feet in some places and 
less in others. Below this is a zone 10 feet in thickness of less advanced 
decay, exposing partially decayed granite in thin sheets. Within this 
zone along the horizontal parting planes and the vertical jointing the 
rock is broken down into light red granitic clay with the middle portion 
of the sheets composed of moderately hard though deeply decayed granite. 
Below this second zone of weathering the granite is a hard, firm and fresh 
rock to the depth of working. 

The rock is a fine-grained, even-textured gray, biotite granite, ap- 
parently free from iron sulphides and oxides or other deleterious minerals 
likely to discolor the stone on exposure. The rock is not entirely mas- 
sive, but displays more or less of the gnessic or schistose structure in the 
quarry, secondarily induced by pressure metamorphism. 

Microscopical Examination. — Under the microscope the rock is com- 
posed, in the order of their abundance, of the principal minerals, feldspar, 
quartz and biotite. The feldspathic constituent consists of the potash 
varieties, orthoclase and microcline, with a nearly equal proportion of 
striated acid plagioclase. Microcline nearly equals orthoclase in amount. 
Intergrowths of the potash feldspar with plagioclase occur. The large 
proportion of single individuals of plagioclase in the granite together 
with the micro-perthite accounts for the excess of soda over the potash 



32 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

shown in the chemical analysis of the rock, quoted below. Twinning 
after the Carlsbad law is sometimes observed in the potash feldspar. 
Overlapping of the periods of crystallization from the magma of the 
quartz and feldspar is indicated in the rather numerous areas of micro- 
graphic intergrowths of these two minerals. In one of the thin sections 
of the rock micropoikilitic structure is fairly well developed in some of 
the potash feldspar individuals. 

Quartz is of the usual granitic kind. Biotite is distributed through 
the sections as deep brown and strongly pleochroic shreds largely altered 
to chlorite. Several shreds of muscovite were noted intergrown with the 
biotite. Alteration of biotite in one of the thin sections is into a color- 
less mica and epidote. Zircon and apatite in the form of small prismatic 
inclusions complete the list of minerals. 

Peripheral granulation is shown in fine-grained mosaics of quartz and 
feldspar filling the interstices between the larger individuals of these 
two minerals. Further mechanical stress is indicated in the undulous 
extinction of the quartz and feldspar. 

The following analysis 10 indicates to some extent the general chemical 
composition of the granite from these quarries : 

Analysis of granite from City quarry, near Raleigh, N. G. 

Si0 2 , 69.28 

A1 2 3 17.44 

Fe 2 3 1.08 

FeO 1.22 

MnO 0.16 

MgO 0.27 

CaO 2.20 

Na 2 3.64 

K 2 2.76 

Jointing occurs at fairly close intervals but the planes are not suffic- 
iently close to prevent the quarrying of dimension stone. The principal 
set of joints strikes approximately east and west. The surfaces of the 
joint-planes are slickensided, coated with a thin veneer of a dull yellow 
colored mineral, probably damourite. 

In the openings the granite is penetrated by very many segregation 
veins, coarse pegmatite and fine-grained aplite. These cut the granite 
indiscriminately, although the larger ones are often more or less parallel 
and conform to an approximate north-south strike. In width the inter- 
secting material varies from a fraction of one inch to, in case of the 

10 Kerr, W. C. Geology of North Carolina, 1875, Vol. I, p. 122. 



THE VARIETIES OF BUILDING STONES. 33 

pegmatites, several feet. A single occurrence of a banded aplite-peg- 
matite was noted, in which the contact was with the enclosing granite on 
one side and the pegmatite on the other. The pegmatites and segregation 
veins are similarly composed of coarse crystallizations of feldspar and 
quartz with occasional biotite. Feldspar predominates and is pink to 
white opaque in color. Biotite is almost entirely absent from some of the 
veins but in larger ones it is present in large platy masses distributed 
oftentimes more or less along the middle portion of the vein. 

Since the formation of the veins the granite mass has been subjected to 
considerable pressure effects, manifested in the folded and crumpled con- 
dition of the veins ; in slight faulting of the veins resulting in a displace- 
ment of as much as six inches in extreme cases ; and in the well developed 
slickensided surfaces of the joint-planes. 

Microscopical Examination of the Pegmatite and Aplite. — A micro- 
scopic study of a thin section of typical pegmatite from the Raleigh city 
quarries shows a composition of feldspar and quartz exclusively, with 
the former greatly in excess. The feldspars are microcline and ortho- 
clase with a slight sprinkling of a striated plagioclase. Microcline is the 
predominant feldspar which shows micropoikilitic structure in many 
instances — observed to a less extent in the orthoclase — consisting of 
quartz and feldspar inclusions. The plagioclase present is mostly as 
included grains in the potash feldspar. Microperthite occurs sparingly 
in the thin section. Mica fails entirely, except several pieces of a color- 
less variety, which is a derived product from the alteration of the feld- 
spar. 

Under the microscope a thin section of the aplite appears quite similar 
to the thin sections of the enclosing granite described above, except that 
the former is very fine-grained and contains a much smaller proportion 
of biotite and plagioclase. Microcline and orthoclase are present in 
nearly equal proportions, with only very little striated plagioclase and 
microperthite shown. Micropoikilitic structure is developed in some of 
the potash feldspars and a few small areas of quartz and feldspar inter- 
growths were noted. The mineral composition of the rock would place 
it among the potash aplites. Biotite of the same microscopic properties 
and mode of occurrence as the enclosing granite is only sparingly dis- 
tributed through, the thin section with an occasional intergrown shred of 
muscovite, and it is much altered to chlorite. Hair-like inclusions of 
rutile are abundant in some of the quartzes. Iron oxide in minute grains 
and crystals is sparingly distributed through the slide. 

Along the west side of the north opening is a large diorite mass sharply 
defined from the granite and cut in all directions by pegmatites and 



34 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

true granite veins, much crumpled and contorted. The pegmatites are 
largest in the diorite mass and again assume large dimensions on the 
east side of the quarry in the granite. The line of contact between the 
granite and the diorite seems to be entirely sharp but exceedingly irregu- 
lar. The exact relations were not entirely plain but from the nearly 
cortinuous exposures of the partially decayed granite over the eastern 
portion of the city of Baleigh and along the street leading to the quarries 
of the same general character as that exposed in the quarries, the writer 
is rather inclined to regard the dioritic mass as intrusive in the granite. 
More evidence is wanted however to verify this statement. In the west 
limits of the city and for a distance of at least 3 miles west and northwest 
the country rock is mica schist highly feldspathic in places, as evidenced 
by the sections made by the roads and railroads in the rock decay. Fresh 
rock is seldom exposed. 

Microscopical Examination of the Diorite. — Microscopic study of a 
thin section of this rock from the quarries described above shows it to be 
a quartz diorite, composed of a large amount of hornblende, plagioclase 
feldspar, and quartz. Hornblende is deep brown and green with strong 
absorption indicated for the brown hornblende in which one or more 
cleavages is well developed. It occurs in irregular elongated forms and 
contains some inclusions. The deep green hornblende shows only im- 
perfect or no cleavage directions, is only feebly pleochroic, and is an 
altered form of the brown hornblende. Extinction angles measured 
against the broad twinning lamellse of the plagioclase corresponds to 
labradorite ranging in composition from Ab 3 An 4 to Ab x An 2 . A con- 
siderable quantity of slightly elongated rounded grains of a colorless 
non-pleochroic mineral with high index of refraction and strong double 
refraction is distributed through the slide in association more or less with 
the hornblende. 

When not jointed and cut by the pegmatitic material, the granite is 
remarkably uniform in texture and color and is a very pleasing and de- 
sirable stone; but, as demonstrated in the Capitol building, dimension 
stone free from the veins cannot be obtained from these quarries. For 
this reason, the rock where opened at present is not suited for general 
building purposes, but it is admirably adapted for street purposes in 
the form of blocks and curbing, into which shapes it can be easily worked. 

THE PENITENTIARY QUARRY. 

This quarry is located inside the enclosure about 1-J miles west of 
the Capitol building and was first opened in 1868. The opening is 
made in a flat-surface exposure of the rock and is roughly circular in 



THE VARIETIES OF BUILDING STONES. 35 

outline having a diameter at the top of from 300 to 350 feet and is re- 
ported to have been worked to a depth of 60 or more feet. During the 
summer of 1903, it was almost filled with water and it had not been 
worked for many years. This quarry furnished stone for the foundations 
and walls of the prison building and for various purposes in the city of 
Raleigh, chiefly for building and curbing. 

The rock is an irregularly banded, light to dark gray, biotite granite- 
gneiss and varies from medium to fine-grained in texture. It is quite 
variable in composition, containing a large proportion of biotite in some 
places and correspondingly dark in color, while in others biotite is but 
sparingly present and the rock becomes a light gray mixture principally 
of feldspar and quartz. Some of the layers are thick and cannot be 
distinguished from typical massive granite of the same texture but as a 
whole the rock mass is finely schistose, the schistosity planes conforming 
to a general north-south strike. 

Two sets of joints of about equal development intersect the rock strik- 
ing about BT.-S., and N". 80° W. For the reason that the opening was 
nearly filled with water and no immediate adjacent exposures of the 
granite-gneiss to the opening were noted, further observations were im- 
possible. 

THE LEWIS PLACE. 

Two miles northwest of Ealeigh and about a quarter of a mile west 
of the public road, are flat-surface and low ledge outcrops of a light gray 
fine-grained granitic gneiss, occurring on both sides of a tiny stream. 
Two small openings were made many years ago, one on each side of the 
stream. The stone quarried is reported to have been used to a small 
extent in several of the older buildings in Raleigh and for foundations, 
curbing and flagstone in the same city. The sills and trimmings in 
Christ Church, Ealeigh, are said to have come from this locality. 

The rock is a hard siliceous gneiss, containing a minimum amount of 
biotite disseminated through it in minute shreds. It is thinly schistose, 
the schistosity conforming to a general N". 10° E. strike. Jointings are 
not conspicuous in the exposures of the rock, but are spaced rather far 
apart and belong to a single set striking N". 80° W. 

Weathered outcrops of biotite granitic gneiss similar to those described 
above are observed at several places along the road for a distance of 5 
miles northwest of the Lewis place. The country rock is apparently 
mica-shist, deeply decayed but preserving in the sections of the decay 
the original schistose structure developed in the fresh rock. The granitic 



36 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

rocks are plainly younger than the schist, and in the few" contacts ob- 
served in the partial decay of the two rocks, the granite cuts across the 
schistosity of the schist. 

THE WTATT-ROLESVILLE GRANITE AREA. 

The Wyatt-Eolesville granite area is located about 14 miles north of 
Ealeigh and about 4 miles south of Wake Forest, extending east from 
Wyatt, a station on the Seaboard Air Line Eailway, to Eolesville, a 
distance of about 5 miles. Flat-surface outcrops of several acres in 
extent are exposed in the vicinity of Wyatt Station and again to the east 
near Eolesville. As indicated below, the granites of this area are biotite- 
bearing but differ in some respects from those to the south in the Ealeigh 
area. 

WYATT STATION. 

From one-half to one-quarter of a miles west of Wyatt's, a flag stop on 
the Seaboard Air Line Eailway, flat-surface exposures of granite occur 
on the E. L. Wyatt property, extending perhaps over a dozen or more 
acres of surface. The exposures occur both on a hill slope and in the 
adjacent valley bottom. 

The rock varies from a medium to a fine-grained biotite-muscovite- 
granite, of light-gray color. The feldspars are of a more or less pinkish 
tone, which impart to the rock, at times, a mixed pinkish-gray color. In 
parts of the area the granite appears to be nearly completely massive 
but in others the schistose structure is strongly developed. Both pyrite 
and garnet are present in the granite, the latter in considerable quantity 
in places. 

The granite is further penetrated by very many pegmatite veins rang- 
ing from a fraction of an inch to two inches in width, and conforming to 
no definite direction but cut the rock indiscriminately. Several sets of 
joints intersect the granite striking N". 20° E., N". 80° E., and approxi- 
mately E.-W. No opening has been made in the exposures of the granite 
and fresh specimens could not be obtained with the hammer. 

EOLESVILLE. 

Five miles east of Wyatt's and one-quarter of a mile S. 40° W. from 
Eolesville on the J. M. Fleming farm is a flat-surface granite mass less 
than a half dozen acres in extent exposed on a gentle southeast slope (five 
degrees). A single small opening has been made along the margin of 
the exposure and a few stones were obtained for local use. 



THE VARIETIES OF BUILDING STONES. 37 

The rock is a biotite granite varying in texture from medium to fine- 
grained, light gray in color with a very faint pinkish tint imparted by 
similarly colored feldspar. Most of the area, however, is composed of 
a uniform medium-textured and pinkish gray granite. 

Microscopical Examination. — Thin sections of this granite under the 
microscope show its composition to be orthoclase, microcline, acid plagio- 
clase, quartz, biotite, occasional shreds of muscovite, apatite, zircon and 
magnetite as primary constituents, with chlorite, kaolin and iron oxide 
as alteration products. Microcline is variable in amount nearly equalling 
in one of the sections the orthoclase. Carlsbad twinning is occasionally 
observed among the potash feldspar. Plagioclase, as finely striated stout 
laths, is freely distributed through the sections in nearly as large pro- 
portion as the potash feldspar. Irregular areas of quartz-feldspar inter- 
growths are rather abundant. Drop-like inclusions of quartz and plagio- 
clase are noted in the potash feldspar in micropoikilitic structure. The 
feldspars show some alterations into kaolin and muscovite. Deep brown 
and strongly pleochroic biotite is distributed through the sections and 
elongated shreds much altered to chlorite and containing inclusions of 
apatite and zircon. Zircon and apatite as prismatic inclusions also occur 
in the feldspar and quartz. 

Jointing is developed at fairly close intervals in several directions but 
not too close to admit of the quarrying of dimension stone. The joints 
strike 1ST. 20° E., and approximately E.-W., the latter set varying a few 
degrees north of west in places. The jointed surfaces are slickensided 
and are covered in places with pyrite, which seems to be absent from the 
rock. Distinct shear zones coincide with the E.-W. jointing, which is the 
direction of the major set of joint-planes. No veins nor segregations 
were observed in any part of the granite. 

BEDFORD FARM. 

About three-quarters of a mile S. 40° W. of Eolesville is a flat-surface 
outcrop on the J. F. Bedford farm, of less than one acre in extent, of a 
light gray slightly pinkish tint, medium fine-grained, biotite-granite. The 
rock is cut in places by a few small veins of pegmatite, and it contains 
some disseminated grains of pyrite. 

Microscopical Examination. — Under the microscope this granite has 
essentially the same composition as that described above on the Fleming 
place, except that plagioclase is only sparingly present and orthoclase and 
microcline make up the f eldspathic constituent with the former in excess. 
Micrographic intergrowths of the quartz and feldspar are quite common. 
Carlsbad twinning is occasionally observed. Biotite is but sparingly 



38 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

distributed through the section, altered in part to chlorite, and much of 
it is leached with the liberated yellow iron oxide quite freely staining 
the section. 

The rock is more closely jointed than the granite outcropping on the 
Fleming place described above, and the shearing has been greater, ac- 
companied by an increased development of pyrite on the slickensided 
surfaces of the joints. Two sets of joints are developed striking 1ST. 20° 
E., and E.-W. The exposure was opened some years ago and some of 
the stone was obtained for sills in the building of Wake Forest College. 

The same rock extends southeastward from this place for a distance of 
at least 5 miles and many large exposures of the same character are 
reported. A number of exposures of granite similar to that already de- 
scribed near Eolesville are reported 2 miles southeast of this place on 
the property of S*. W. Terrell. 

Diabase. — One mile northeast of Eolesville on the farm of Moses 
Williams, a diabase dike approximately 100 feet wide and striking 1ST. 20° 
E. penetrates the granite similar to that found to the southwest of 
Eolesville. 

FRANKLIN COUNTY. 

Exposures of granite are numerous over the middle and eastern por- 
tions of Franklin County, especially in the vicinity of Louisburg, the 
county-seat. Louisburg is located in an extensive granite area, out- 
crops of which occur along the various roads leading in all directions 
from the town. Usually the rock is deeply decayed yielding a typical 
light gray to deep red granitic product by which the granite may be 
readily traced over the surface. Fairly fresh granite is exposed in im- 
mense boulder outcrops and somewhat irregular small surface-masses. 
Both the normal even-granular granite and porphyritic granite occur, 
the former making up much the greater part of the rock exposed in the 
County. Porphyritic granite was noted at only one or two places. 

~Ro quarries have yet been opened at any locality in the county, but 
several small openings have been made along Tar Eiver at Louisburg, 
from which some stone was quarried to supply a local demand in the 
town. 

THE LOUISBURG GRANITE AREA. 

Louisburg has a nearly central position in the granite area of Franklin 
County. It is the county-seat and is located directly on Tar Eiver, a 
large stream which cuts across the granite area. The town is further 
located about 10 miles east of Franklinton, a station on the main line of 



THE VARIETIES OF BUILDING STONES. 39 

the Seaboard Air Line Bailway, between which towns a branch line of 
the Seaboard is operated. For convenience of description this granite 
area is here designated the Louisburg granite area. 

On the east the area is bounded by an extensive north-south strip of 
crystalline schists and volcanics. It extends westward to within a short 
distance of Franklinton on the Seaboard Air Line Eailway. To the north 
and south, the limits of the area have not been definitely traced, though 
its southward extension may probably include the granite outcrops along 
Moccasin Creek, in the extreme southeastern portion of the County and 
extending into the adjacent northeast corner of Wake County. 

The rock is a medium coarse to fine-grained biotite granite of light 
gray color. In places the feldspars have a pronounced pinkish tint, im- 
parting a similar color to the granite. The granite is even-granular in 
texture and over most of the area it is decayed to some depth. 

The decay consists for the most part of a light gray soil, stained in 
places a rusty brown, in which nearly fresh particles of the essential 
minerals of the fresh rock may be easily identified. This zone passes 
at a moderate depth into partially though advanced decayed granite 
easily broken by very light blows of the hammer. The feldspars are dull 
and opaque more or less kaolinized. A slight leaching of the biotite 
is visible in which slight staining of the areas immediately surrounding 
the individual shreds of this mineral, from the liberated iron oxide. 
The partially decayed granite is exposed at many points along the road 
leading west from Louisburg, from blasting in grading the road. Per- 
haps the best exposure of the partially decayed rock is at the bridge 
over Tar Eiver just across from Louisburg. 

Exposures of the nearly fresh granite occur along the river road be- 
ginning about 4 miles northeast of Franklinton and continuing into 
Louisburg. Along the same road, at distances of 3 and 2J miles, re- 
spectively, northwest of Louisburg, the outcrops are especially noteworthy. 
The exposures are in the form of immense boulders and flat-surface 
masses, and are rather numerous over parts of the Kufrm place one to 
2 miles west of Louisburg. 

On the west side of Tar Eiver about 200 paces from the Louisburg 
bridge considerable blasting has been done recently in grading the road, 
and the partially decayed granite was utilized for macadam on the road. 
An excellent section 12 to 15 feet in depth in the partially decayed rock 
is exposed on the south side of the road near the bridge in which the 
jointing is shown to advantage. The joint-planes are spaced at close 
intervals striking K-S., 1ST. 80° E., and N". 20° W., the last set being 
apparently less conspicuously developed than the other two. 



40 BUILDING AND OENAMENTAL STONES OF NORTH CAROLINA. 

Within the limits of Louisburg, a few hundred paces south of the 
bridge and immediately on the east side of the river, in the rear of the 
county jail, two small openings were made many years ago in low ledge 
outcrops of the granite. The jail was built of the stone quarried from 
the largest of these openings. The granite is penetrated in both openings 
by many pegmatite veins which do not conform to any given direction and 
which vary from an inch to 6 inches in width. These veins are com- 
posed of coarse crystallizations of quartz and feldspar, the latter pre- 
dominating, through which are distributed scattered light-colored plates 
of mica. Two sets of joints intersect the granite striking 1ST. 80° W., 
and K 20° W. 

Microscopical Examination. — A thin section of the rock from the 
Louisburg openings in the rear of the county jail showed a medium- 
textured biotite granite, composed of the principal minerals orthoclase, 
microcline, acid plagioclase, quartz, biotite, muscovite, apatite, zircon, 
iron oxide, chlorite and kaolin. 

Orthoclase is the predominant feldspar with but little microcline, but 
much striated acid plagioclase is distributed through the section. More 
or less alteration of the feldspathic constituent to muscovite and kaolin 
is noted. The simultaneous crystallization of a portion of the feldspar 
and quartz is indicated in the irregular areas of micrographic inter- 
growths of quartz and feldspar. Prismatic inclusions of apatite and 
zircon characterize to some extent each of the three principal minerals, 
namely, feldspar, quartz and biotite. Biotite is of the usual kind, 
partially altered to chlorite and it is associated with occasional shreds 
of muscovite. 

Along the Louisburg-Franklinton road, which follows closely the rail- 
road in an east-west direction between the two towns, numerous outcrops 
of the same granite occur. At the railroad crossing by the wagon road, 
3^ miles west of Louisburg, blasting was necessary and many large 
masses and blocks of the medium gray, moderately fine-textured granite 
are scattered over the surface. Occasional rounded pinkish feldspar 
phenocrysts are distributed through the granite, but it is essentially an 
even-grained granite of desirable quality. It differs from the granite 
opened in Louisburg in being a shade darker in color and containing 
some pinkish feldspar. In general appearance the rock is not very unlike 
that quarried at Greystone in Vance County, except that it is entirely 
massive. 

Microscopical Examination. — Under the microscope the thin section 
indicates a medium fine-textured biotite-granite, composed of orthoclase, 
a little striated plagioclase, quartz and biotite, the latter largely altered 



THE VARIETIES OE BUILDING STONES. 41 

to chlorite. Biotite shows further alteration in several cases into a color- 
less mica. Microcline and microperthite are absent from the section 
and in this respect differ from the thin sections examined from the ad- 
joining counties in this part of the State. Orthoelase shows some twin- 
ning after the Carlsbad law. Both feldspars indicate considerable alter- 
ation, principally, into kaolin. Both micropoikilitic and micrographic 
structures are sparingly developed in the feldspars. The usual occurrence 
of zircon and apatite appears. Inclusions are rather common in the 
three essential minerals quartz, feldspar and biotite. Considerable alter- 
ation of both the biotite and the feldspars is marked, and the fracture 
lines crossing the light-colored minerals are in some cases stained yellow 
from the liberated iron oxide of the biotite. No injurious or harmful 
minerals were noted in the thin section of this granite. 

This granite is apparently a desirable stone for general building pur- 
poses and quarries might be advantageously worked in almost any of 
the principal outcrops. It extends along Tar Biver southeastward to 
near Springhope in Nash County and is again reported along Moccasin 
Creek in Franklin and Wake counties. 

Porphyritic Granite. 

About 4 miles northeast of Franklinton on the Simms bridge road, 
small outcrops of a coarse-textured porphyritic biotite granite occur on 
the Wiley place. The rock is light gray in color and in an advanced 
stage of decay not permitting the collecting of fresh specimens. The 
phenocrysts are large feldspars more or less idiomorphic in outline and 
pink in color. Biotite inclusions of the groundmass are developed in 
the phenocrysts. No opening has been made and this constitutes the 
only area of true porphyritic granite noted in the County, although a 
porphyritic tendency is indicated in several granite exposures to the 
west of Louisburg. 

Dikes of Basic Igneous Rocks. 

Along the two roads mentioned above between Franklinton and Louis- 
burg, the granite is intersected in a number of places by basic dikes of 
the diabase type; but only the more important ones are mentioned. 

Two miles northeast of Franklinton on the Simms bridge road, a 
diabase dike of considerable width and trending northwest cuts the 
granite. Four miles west of Louisburg on the river road, a second dike 
approximately 25 feet wide and having a northwest strike is observed 
penetrating the granite. Three and a half miles east of Franklinton on 



42 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

the Louisburg-Franklinton road a coarse-grained diabase dike about 350 
feet wide is exposed for some distance on both, sides of the road, on the 
Green place. Its trend is northwest and it cnts the granite. (Eesults 
of tests of this rock for road material are given on p. 265). Again at the 
railroad crossing in front of the Parnell house, a fine-grained diabase 
dike is crossed by the wagon road and is exposed in a shallow cut along 
the railroad, conforming to a general northwest strike. 

Microscopical Examination. — Under the microscope a thin section of 
the rock from the large dike 3J miles east of Franklinton shows a typical 
olivine diabase. It is composed of slender but long stout laths of 
striated plagioclase, whose extinction angles measured against the 
twinning lamellae correspond to labradorite varying in composition 
from Ab-L An x to Abj An 3 ; large partially idiomorphic plates of green- 
ish augite filling the interstices, olivine and a little magnetite. The 
augites always show good cleavage development in one direction and at 
times both cleavages are well developed. By polarized light it is of light 
greenish color, some of which is moderately strongly pleochroic, from 
red to green. The olivine usually occurs in more or less aggregated 
areas in association with the augite, considerably altered along the cracks 
to serpentine. In some instances only small particles of the fresh olivine 
appear in the black mass of serpentine. 

WARREN COUNTY. 

The most important exposures of granitic rocks in Warren County are 
found at Warrenton, the county-seat, and to the north and northwest 
of Warren Plains, a station on the Seaboard Air Line Eailway. A few 
stones have been quarried in each locality, but no regular quarries have 
been worked in the County. 

WARRENTON AREA. 

Small exposures of a dark gray biotite-hornblende-gneiss occur at 
several places near together, just beyond the west limits of the town. 
The rock is irregular in structure and composition, and is only suited 
for rough grades of work. A rock crusher is located at the opening and 
the stone quarried is crushed and used for macadamizing the streets of 
Warrenton. Two sets of joints intersect the gneiss striking N". 30° W., 
and N". 60° E. 

A second opening is made in an outcrop about a quarter to a half 
mile south of the one described above. This one was worked in 1867-^68 
for stone to build the county jail. Jointing is well developed and some 
scattered crystals of pyrite are observed in the rock. 



THE VARIETIES OF BUILDING STONES. 43 

Microscopical Examination. — Microscopic study of a thin section of 
the rock reveals a fine-textured biotite-hornblende gneiss, in which the 
parallel arrangement of the minerals in a given direction is pronounced. 
Besides biotite and hornblende, the principal minerals in the rock are 
orthoclase, with an equal or greater amount of striated plagioclase, 
quartz, epidote, and chlorite. Microcline entirely fails. The hornblende 
nearly equals biotite in amount, and when unaltered it is deep brown 
and pleochroic, with the prismatic cleavages well developed. Much of 
it is altered to the deep green or bluish green "reedy" hornblende. 
Biotite is of the usual kind. Some epidote, resulting from the inter- 
action of the ferro-magnesian minerals and the feldspars, is present. 
Considerable chlorite is distributed through the section as a derived 
product from the alteration of biotite. Quartz is equal to or greater 
in amount than the feldspathic constituent. A slight sprinkling occurs 
of the usual microscopic accessories. 

THE WARREN PLAINS AREA. 

About 2 miles north of Warren Plains, a station on the Seaboard 
Air Line Railway, are several exposures of granite near together, on the 
Norwood place. The largest outcrop extends over less than one-half 
acre of surface from which a few stones were quarried some years ago 
for foundations in- the neighborhood. 

The rock is a fine, even textured, nearly white muscovite-granite. The 
mica is of a decided yellowish color with a slight green tinge, and con- 
trasts rather strongly in color with the light-colored quartz and feld- 
spar. It is only sparingly distributed through the rock as small irregular 
plates. 

Microscopical Examination. — A thin section of the ro'ck examined un- 
der the microscope revealed a fine-grained muscovite granite composed 
of orthoclase, quartz, much broad and finely striated acid plagioclase, a 
few pieces of microcline, occasional microperthite intergrowths, mus- 
covite, some garnet, and iron oxide. Feldspar is the predominant con- 
stituent, with much quartz and very little muscovite. Occasional in- 
clusions of the usual microscopic accessories were observed. 

The granite is massive, quite uniform in color and texture, and con- 
tains so far as could be observed no injurious minerals. Jointing is well 
developed in three directions, spaced at rather close intervals, and strik- 
ing N". 60° W., K 45° E., and "N". 10° E. Jointing is not, however, 
too closely spaced to prevent the quarrying of large blocks. Outcrops 
of the same granite occur nearby on the Norwood and the adjoining 



44 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

farms. While the exposures are largely in the nature of flat-surface 
masses, boulder outcrops are not entirely lacking. 

About one-quarter of a mile east of the Eichmond division of the 
Seaboard Air Line Kailway, one mile northwest of Wise siding and 
about 1-J miles northwest of the granite exposure on the Norwood 
place described above, is a small opening in a biotite muscovite- 
bearing granite of somewhat coarser texture. The outcrop is on the 
Paschal place, and some of the stone was quarried from it during the 
winter of 1903 for general building and street purposes. 

The rock is a medium light gray massive granite and of medium 
texture. It is coarser in texture and darker in color than the granite 
described above on the Norwood place. Biotite is regularly distributed 
through the rock and in places much red garnet is present, indeed so 
abundant in some of the hand specimens of the granite that a mixed 
pink and gray color is imparted. It should prove to be a desirable 
granite for general building purposes. 

Microscopical Examination. — Microscopic study shows the rock to be 
a fine-textured biotite granite containing occasional shreds of muscovite. 
The other minerals are orthoclase, microcline, some striated acid plagio- 
clase, a few pieces of microperthite intergrowths, quartz, titanite, zircon, 
apatite, and rutile, and much chlorite derived from the biotite. Zonary 
structure characterizes the feldspar in some instances and is beautifully 
brought out in the alteration along parallel lines in the individual feld- 
spar grains. Some of the feldspar is further characterized by Carlsbad 
twinning and micropoikilitic structure. Only a single rounded area of 
quartz-feldspar intergrowth was noted. Hair-like inclusions of rutile 
are abundant in most of the quartz. Biotite of the usual brown color 
and strong pleochroism is largely altered to chlorite. Much colorless 
mica is distributed through the section as an alteration product derived 
from the biotite and the feldspars. Inclusions are frequent in the feld- 
spars, quartz and biotite. 

VANCE COUNTY. 

The granite of Vance County is perhaps amongst the best known in 
the State, and some of the quarries compare favorably with the most 
extensive ones in North Carolina. The area is a large one confined 
principally to the central and eastern parts of the County. Quarries are 
worked at several places in the County along the Seaboard Air Line Kail- 
way, chiefly at and near Greystone and Middleburgh stations. The 
quarries at Greystone have been worked almost continuously since they 



THE VAEIETIES OF BUILDING STONES. 45 

were first opened about 20 years ago. Those near Middleburgh have 
only recently been opened. Within the past year a little of the granite 
has been quarried at Henderson, the county-seat, for street purposes. 

The granite from the various quarries in Vance County has been used 
mostly for street purposes in the form of blocks ; for coping and bridges ; 
and to a less extent as a building stone. It has been shipped to numerous 
places in Virginia and North Carolina, especially to the eastern towns 
in these two States. The quarry waste is used for macadam and ballast. 

THE GREYSTONE GRANITE AEEA. 

The Greystone quarries are located at G-reystone, a station on the 
Seaboard Air Line Railway, 4 miles north of Henderson, the county- 
seat. They are the largest and best known quarries in eastern Carolina, 
and are located, with one exception, on the east side of the railroad. 
As shown below under the individual descriptions, the rock is a schistose 
granite, which works well and is admirably suited for street purposes 
for which there has been a large demand over the eastern Carolina- 
Virginia territory. 

Microscopical Examination. — Microscopic examination of thin sections 
prepared from hand specimens of the rock collected from the various 
quarries around G-reystone shows remarkable similarity. The rock is 
a biotite granite in which the schistose structure is more or less apparent 
in each of the thin sections, best emphasized in the biotite which is ar- 
ranged along roughly parallel lines coincident with the longer axis of 
the individual filaments and shreds. The arrangement along parallel 
lines is much less apparent in the light-colored constituents. The prin- 
cipal minerals are quartz, orthoclase, microcline, occasional plagioclase 
near oligoclase, brown biotite, a little muscovite, and considerable in- 
clusions of zircon and apatite. Much chlorite and kaolin are developed 
from the alteration of the biotite and feldspars, respectively. Also, with 
the exception of several intergrown shreds of muscovite with the biotite, 
the muscovite is entirely derived from the alteration of the feldspars. 

' Feldspar is the predominant constituent, consisting largely of ortho- 
clase and microcline with many intergrown stringers of an acid pla- 
gioclase. A subordinate amount of striated plagioclase individuals, whose 
extinction angles indicate oligoclase, is shown in most of the slides. In 
many cases the potash feldspars display micropoikilitic structure and 
occasional twinning after the Carlsbad law. The feldspathic constituent 
is more or less clouded with irregular patches and areas of kaolin and 
minute scales of muscovite. The quartz and feldspar are frequently 



46 BUILDING AND ORNAMENTAL STONES OF NOETH CAROLINA. 

intergrown in micrographic structure, clearly indicating that the period 
of formation of the quartz began before that of the feldspar closed. 

The biotite is deep brown and strongly pleochroic. It bleaches to 
green on alteration and is largely altered to yellow-brown and brown, 
nearly black, opaque chlorite. Its usual occurrence is in elongated 
shreds and in amount it is much less than quartz or feldspar. Inclusions 
are somewhat frequent in the three principal minerals quartz, feldspar, 
and biotite. The microscopic accessories present no noteworthy features. 

THE OLD GREYSTONE QUARRY. 

This quarry, owned by P. Linehan and Sons, is the largest one in the 
County, and is located on the west side of the Seaboard Air Line Kail- 
way near the depot at Greystone, with which it is connected by a spur 
track. It was opened more than 20 years ago and was regularly worked 
for the first 15 years, but operations have been suspended for the past 
5 years. During the period of operation it was well equipped with 
steam derricks, drills and hoisting engines for quarrying and handling 
the stone. The opening covers about 2 acres of surface in extent worked 
to an average depth of 35 feet. 

The granite decay at the surface, including soil, will average about 
three feet in thickness. A much greater thickness is attained in some 
places, as much as 15 feet in extreme cases, and it is thinner in 
others. Near the top of the opening the rock weathers into thin hori- 
zontal sheets or bands, which become much less well defined lower down. 
Near the bottom the sheets thicken to as much as 12 and more feet. 
Jointed structure is well defined in one direction, N". 60° E., and cuts 
the rock at irregular distances or intervals. In some places zones of 
close jointing spaced at intervals of several feet occur, but over most of 
the quarry the joints are spaced at wide intervals and stone of almost 
any dimensions can be quarried. The surface of the joint-planes are 
often smooth, more or less polished and striated from movements of 
the blocks. They are coated with a thin veneer of the usual dull yellow- 
ish-green mineral matter, probably damourite in part, a dynamic altera- 
tion product derived from the original minerals of the granite. 

The granite is further penetrated by very many veins and dikes which 
vary in width from less than one inch to many inches. They include 
segregation veins, pegmatite and fine-grained granite dikes. In strike 
they conform, as a rule, to a north-south direction. Pink feldspar forms 
the most abundant mineral in the veins and dikes, and they all contain 
some biotite, present as large platy masses in the pegmatite and as very 



THE VARIETIES OF BUILDING STONES. 47 

small shreds in the fine grained dikes. Quartz is variable in amount, 
but never entirely fails. Small irregular, roughly rounded dark-colored 
bunches of segregation areas of biotite were occasionally noted in the 
granite. Apart from the pronounced finely schistose structure of the 
rock, pressure-metamorphism has produced a marked tendency toward 
segregation into alternating dark micaceous bands with lighter colored 
ones of quartz and feldspar. The strike of the schistosity is, in general, 
north and south. 

The rock is a fine-grained biotite granite-gneiss with a pronounced 
porphyritic tendency. It is dark gray in color with a pinkish cast im- 
parted by the prevailing pink colored feldspars. On close inspection 
the rock shows a rather decided mixed pink and gray color. The felds- 
pathic constituent is in larger sized individuals than the other mineral 
components of the rock. Biotite occurs in very small black lustrous 
shreds orientated in a parallel direction to their longer axes. 

The granite from this quarry has been shipped to numerous places 
in Virginia and North Carolina, where its principal use has been in 
the form of blocks and curbing for street purposes; for coping and 
bridges; and to a limited extent for a general building stone. 

THE NEW GREYSTONE QUARRY. 

This quarry is located approximately 150 yards west of the Old Grey- 
stone quarry described above and is owned by the same company. It 
was opened in the fall of 1902, and in June 1903, the opening covered 
less than one-half acre of surface in extent, and had been worked to an 
average depth of less than 12 feet. 

The fresh rock is covered to 4 depth of 3 to 6 feet of soil and 
decaved granite, which makes stripping necessary to this depth, in 
quarrying. Two sets of joints striking N". 60° E., and N". 5° -10° E., 
intersect the rock. The latter set of joints is less well defined than the 
former. Unlike the Old G-reystone quarry nearby, only occasional inter- 
secting pegmatite veins were exposed in the opening. These are in all 
respects similar to those described above penetrating the granite of the 
other quarry, composed of pink feldspar and quartz with a little copper- 
to lighter colored mica, biotite. No free sulphides or other injurious 
minerals likely to discolor the rock on exposure are present in any of the 
granite in this quarry. 

The rock in this opening is the same as that quarried in the old open- 
ing nearby. The results of the microscopical examination of thin sec- 
tions of the granite from the two quarries are given on page 45. The 



48 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

pinkish feldspars give a similar tint to the gray rock, which on close 
inspection appears to be of a more or less mixed gray and pink color. 
The texture of the granite is the same for the two openings, but the 
rock of the new opening is perhaps slightly less schistose and more 
massive in places with correspondingly more uniformity in color than 
that of the old one. 

The granite from this quarry is shipped to Norfolk and Portsmouth, 
Virginia, where it is used for street purposes in the form of blocks or 
curbing. A rock crusher is operated at the quarry for working up the 
waste for use in granulithic work. 

THE GREYSTONE GRANITE AND CONSTRUCTION COMPANY'S QUARRY. 

This quarry is located at the base of a slight slope about three-fourths 
of a mile northwest of the depot at Greystone. The hill-slope back of 
the quarry rises some 25 to 30 feet above the opening. The quarry was 
first opened in 1889 and was worked constantly for about 6 years, but 
has been idle for the past 5 or more years. At the time of working 
it was well equipped with the necessary modern machinery for quarrying 
and handling the stone, and a railroad spur was laid and operated between 
Greystone and the quarry. The opening is a large one averaging nearly 
250 feet each way and worked to a depth of about 25 feet. 

The opening shows along the face decay from the surface downward 
for 2 to 10 feet in depth, composed largely of a granite soil of red 
to light gray color and thin partially decayed nearly horizontal sheets 
of moderately firm rock. As in the Old Greystone quarry, the horizontal 
parting planes are less well defined lower down in the fresh rock, al- 
though they are variable, separating the rock into layers or sheets 8 
or 10 feet thick. Two sets of jointS of about equal development and 
intersecting at right angles cut the granite approximately N.-S.,*and 
E.-W. These greatly aid in the quarrying of the stone and are suf- 
ficiently spaced to admit of any desirable size blocks being quarried. 
Pegmatite veins 6 to 8 inches across in the larger ones penetrate 
the granite striking in a general north-south direction. Small irregular 
segregation areas of black mica are sometimes noted in the rock. 

The rock is essentially the same as that of the Linehan quarries de- 
scribed above. It is somewhat lighter in color, but has a pinkish 
tone, varying from fine to medium-grained in texture, and distinctly 
schistose in structure. The schistosity conforms to a general north- 
south direction. The feldspars will average larger in size than the other 
mineral constituents and is white or of light color with the usual por- 
phyritic tendency indicated. The biotite occurs in somewhat larger 



THE VAKIETIES OE BUILDING STONES 49 

plates than that of the Linehan quarries described above, and it is highly 
lustrous and black in color. 

So far as it was possible to learn, the granite from this quarry was 
worked principally into blocks for use in various towns in the Southern 
States. The good qualities of the granite are well shown in a block of 
the stone with polished and dressed faces on exhibition in the State 
Museum in Raleigh. 

THE SEABOARD AIR LINE RAILWAY QUARRY. 

The railroad quarry is located in a broad but slight depression oc- 
cupied by a small stream, about 2 miles northeast of G-reystone sta- 
tion. In all, several acres of surface have been stripped to a moderate 
depth over the gentle slopes on both sides of the small stream. It was 
first opened about 3 years ago and was worked for 6 or 8' months 
by the Seaboard Air Line Railway. Operations were then suspended 
for about one year when work was again resumed under lease and con- 
tinued for some 8 or more months. It has not been worked during 
the past year. A spur track is laid from the main line near Greystone 
to the quarry, a distance of about 1-J miles. The quarry is in very bad 
shape and indications point to very poor judgment in working it. 

Three rather strongly contrasted phases of the granite are developed 
in the rock of this quarry. The first, which comprises the main body 
of the rock, is the typical Greystone granite, dark gray in color with a 
faint pinkish tone and generally fine-grained in texture. In the hand 
specimens the schistose structure is much less marked than in the Grey- 
stone rock proper, and it exhibits a pronounced porphyritic tendency. 
The second phase is a medium-textured, uniformly light-pink granite 
containing a much smaller amount of biotite than the first. The rock 
is decidedly schistose in structure, highly feldspathic, and the biotite is 
distributed along roughly parallel disconnected bands of knife-edge 
thickness. As nearly as could be determined, the width of this zone as 
exposed in the opening is not less than 600 feet, with a north-south 
direction. The porphyritic tendency noted in the first phase of the 
granite is not shown in the second one. The third and last phase is a 
dark blue-gray biotite-granite generally finer grained than the other two 
and containing a larger amount of biotite. This phase of the rock is 
usually developed as a narrow zone varying from 2 to 6 feet across 
between the pink and the gray granite. 

The three phases of the granite in this quarry are each alike schistose 
in structure, the schistosity striking north and south; and the jointing 



50 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

is likewise continuous through them in the same general directions. 
While the quarry is not sufficiently developed to conclusively state the 
exact relations and significance of these three variations in the rock, 
such data as were available would seemingly indicate that they are 
phases of the same rock as stated above and are not separate intrusions. 
The differentiation was possibly begun with the cooling of the magma and 
completed by the intense dynamic metamorphism to which the granite 
has been subjected. Indeed banding on a small scale, differentiation 
into dark and light colored bands, due to metamorphism are distinctly 
noticeable in some parts of the quarry. 

Three sets of joints intersect the granite striking N.-S., E.-W., and 
NW.-SE. Jointing in the E.-W. direction forms the major set of planes 
and the surfaces of this set are usually slickensided after the fashion of 
those described above in the Old Greystone quarry. Intersecting mate- 
rial of pegmatitic composition penetrates the granite rather frequently, 
varying from one inch to more than 6 inches across and in most cases 
conforming to a strike of N. 10° E. 

The stone quarried from this opening is reported to have been used 
both for ballast and for street purposes. 

One other exposure of the granite near Greystone station between the 
main track of the railroad and the New Greystone quarry was recently 
opened to a small extent, but was shortly abandoned on account of the 
numerous veins and the irregular texture of the rock. 

THE MIDDLEBURGH GRANITE AREA. 

Two quarries, near together, have recently been opened on the west 
side of the Seaboard Air Line Eailway, one mile west of Middleburgh 
station and about 3 miles north of Greystone on the estate of James 
E. Carroll. The granite is essentially the same as that quarried at Grey- 
stone. On the whole it probably contains a very slightly increased 
amount of biotite and is correspondingly darker in color. The feldspars 
are chiefly light in color or white with only the barest pinkish cast ob- 
served. It is fine-grained in texture, displaying a marked porphyritic 
tendency in the feldspathic constituent. The biotite is distributed in 
fine black shreds along parallel lines arranged in the direction of their 
longer axis. Hand specimens from the two openings are indistinguish- 
able. 

Microscopical Examination. — Under the microscope the thin sections 
of the granite from the Middleburgh quarries are as closely identical in 
all respects with those from the Greystone quarries as is possible. The 









. 



THE VARIETIES OF BUILDING STONES. 51 

rock is a biotite granite distinctly schistose and composed of the same 
minerals in practically the same proportions as the Greystone area. 
Feldspar predominates consisting of the potash varieties, orthoclase and 
microcline, with micro-perthitic intergrowths and occasional individuals 
of an acid plagioclase. Some alteration to kaolin and muscovite is in- 
dicated in the cloudy and opaque areas over the feldspar surfaces. 
Micropoikilitic structure in the potash feldspars is common and Carlsbad 
twinning is occasionally observed. Micrographic intergrowths of quartz 
and feldspar, indicating the overlapping of the periods of separation 
from the magma of these two minerals, are frequent. Biotite is largely 
altered to chlorite and it is identical in occurrence and microscopic prop- 
erties with that in the Greystone granite described above. The micro- 
scopic accessories are the same in the granite from the 2 areas. 

The first quarry was opened in 1899 and is located about 
150 yards from the Carroll residence. The opening will average 
about 400 feet long by 199 feet wide, and has been worked to an average 
depth along the quarry-face of 25 feet. A 22-foot quarry-face is devel- 
oped lengthwise of the opening, covered at the top by an average depth 
of about 4 feet of a granite soil derived from the decay of the rock. 
A small force was working during the summer of 1903 and the quarry 
has been worked a part of each year since it was first opened. 

Only one set of joints cuts the granite striking E.-W., and these are 
spaced at some distance apart, less than a half dozen planes being visible 
in the entire quarry. Very few seams were noted in the rock. A 
tendency toward banding is indicated in places, separation into alternat- 
ing darker and lighter colored layers, in a direction ST. 20° E., which 
is the prevailing strike of the schistosity. 

The rock is a granite-gneiss of dark-gray color, containing perhaps 
a slightly larger proportion of biotite than that quarried at Greystone. 
It is fine-grained and is remarkably uniform in both color and tex- 
ture. The feldspars are mostly white and show much less of the pink 
color so characteristic of the former area. The rock works readily and 
seems admirably suited for the use made of it. 

The stone quarried up to date has been shipped mostly to Norfolk and 
Portsmouth, Virginia, in the form of blocks and curbing for street pur- 
poses. It has also been used to a limited extent in buildings. The 
method of quarrying is by steam drilling and blasting. 

A second opening was made in an outcrop of the same granite in 
1903, exposed along a small stream 125 yards east of the Carroll resi- 
dence and 100 yards south of the opening described above. Quarrying 
had begun only in May, 1903, and the opening was a small one. The 



52 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

sap, partially decayed granite, is only a few inches thick, which is shown 
in the partial discoloration from weathering. The rock is perhaps a 
shade coarser in texture in places than that of the nearby opening and 
the feldspars are prevailingly light in color with only the faintest pinkish 
tone discernible. Jointing and schistosity are the. same as noted in the 
other opening already described. In all other respects the rock is 
identical in the 2 openings. 

A small force was at work quarrying the granite in June, 1903, and 
the stone in the form of blocks and curbing was being shipped to Nor- 
folk and Portsmouth, Virginia, for use on the streets. The stone from 
these 2 openings is hauled by teams to Middleburgh, one mile distant, 
where it is loaded on the cars for shipping. 

THE HENDERSON GRANITE AREA. 

The G-reystone granite-gneiss extends southward 4 miles to Hender- 
son, the county-seat of Vance County, where it is exposed in and be- 
yond the northwest limits of the town, along the road. It has been 
opened to a slight extent on the western edge of the town affording op- 
portunity for studying the fairly fresh rock. Some variation is observed 
in the rock at this point from that quarried further north at Greystone 
and Middleburgh. It has been more affected by pressure-metamorphism, 
and is accordingly an irregularly banded pink and gray granite-gneiss 
of fine to medium texture. In places it is more feldspathic and shows 
decreased biotite over the Greystone rock. The contorted bands of 
biotite contain occasional irregularly rounded feldspar phenocrysts. 

Microscopical Examination. — The thin sections under the microscope 
indicate the presence of the same minerals and structure as noted in 
those of the granite from the Greystone and Middleburgh quarries, ex- 
cept that no plagioclase as single individuals is observed and the micro- 
poikilitic structure of the potash feldspars is less well defined. The 
thin section indicates, as in the field examination of the rock, effects 
of greater pressure-metamorphism than in the Greystone and Middle- 
burgh quarries. 

Two sets of joints cut the rock in this exposure, the major set strik- 
ing Is. 25° E., and a less well developed set striking N". 70° W. The 
general strike of the schistosity is N. 25° E. The surfaces of the joint- 
planes are coated in places with much epidote. The rock in this exposure 
is only suitable for very rough grades of work, such as macadam and 
ballast. 

Outcrops of a similar granite to that quarried at Greystone are re- 



THE VARIETIES OF BUILDING STONES. 53 

ported in the vicinity of Williamsboro, in the same County, some 10 
or more miles northeast of Henderson. The exposures occur some dis- 
tance from the railroad and have not yet been opened, so that no definite 
statement can be made concerning them. 

GRANVILLE COUNTY. 

Granite boulders of light-gray color and medium texture are reported 
occurring in the vicinity and to the east of Oxford, the county-seat of 
Granville County. No quarries have been opened, but some of the 
larger boulders have been split and worked into curbing and foundation 
stone and for other purposes for local use. Owing to the large territory 
to be covered and the very limited time devoted to the field work, no 
detailed studies of the outcrops could be made. 

RESUME OF THE GRANITES OF THE NORTHEASTERN CAROLINA 

GRANITE BELT. 

To recapitulate, it will be observed from the above detailed descrip- 
tion of the granitic rocks in the 5 counties composing this belt, that 
extensive workable areas of different grades of granite are found, suited 
for all grades of work in which granite is used, except for the better 
grades of monumental stock. Systematic quarrying has been limited 
principally to areas in two counties of the belt, namely, in and around 
Raleigh in Wake County, and at and near Greystone and Middleburgh 
in Vance County. Quite a large supply of the stone has been quarried 
from both areas and the quarrying operations extend back over a long 
period of years, supplying a local demand for the stone in eastern 
Virginia and Carolina. The quarries opened are most favorably located 
with reference to the principal lines of railroad traversing the belt, af- 
fording ample and convenient transportation facilities. The granite 
outcrops are rather numerous over most of the belt and they are, in 
many instances, of sufficient size to admit of large quarries being opened 
without occasioning much surface stripping. Jointing in the granite 
is rarely close enough to render the quarrying of dimensional stone im- 
possible. In several places, however, the rock is so freely penetrated by 
dikes and veins of pegmatite as to make it impossible to obtain dimen- 
sion stone free from them. Deleterious minerals, such as free sulphides 
and iron oxides, which are a source of discoloration to stone on exposure, 
are practically absent from the granites of this belt. 

The granites show but little variation in mineral composition over the 
entire area. With only one exception they are biotite-granites, contain- 



54 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

ing occasional muscovite, and in 2 places hornblende is present. The 
exception noted is a muscovite granite occurring on the Norwood place 
2 miles northwest of Warren Plains in Warren County. In texture 
the rocks vary from medium- to fine-grained, with porphyritic tendency 
noted in places. True porphyritic granite, however, is found at only one 
locality in the belt, namely, in Franklin County. Structurally, they vary 
from massive to schistose rocks, and are some shade of gray with a pro- 
nounced pinkish tone over much of the area imparted by similarly 
colored feldspars. 

Microscopically, the essential minerals in the order of their abundance 
are feldspar, quartz, and biotite. Plagioelase is present in all the thin 
sections examined and it is usually present in considerable quantity. 
Microcline may occasionally entirely fail but it is usually present in 
large amount nearly equalling in many instances the orthoclase. Poi- 
kilitic, perthitic, and graphic micro-structures are developed to some 
degree in nearly all the thin sections studied. Both the feldspars and 
the biotite show some alteration in the sections to the usual secondary 
products derived from these minerals. The component minerals of the 
granites are closely and complexly interlocked, imparting thereby great 
strength and durability to the stone. 

The quarried stone has been used principally for street purposes in the 
form of blocks and curbing, and for general building purposes, and in a 
number of other less important ways. Still another important use made 
of the stone is for macadam on the streets and the roads. 

THE CAKOLINA METAMOEPHIC SLATE AND VOLCANIC 

BELT. 

GENERAL DESCRIPTION OF THE BELT. 

The area of metamorphic slates and schists and altered volcanic rocks 
includes a belt extending in a general southwest direction across the 
middle portion of the State which forms a part of the eastern Piedmont 
plateau region. It varies in width from 8 to 50 miles and is included 
between the Carolina igneous belt on the west and principally by the 
Triassic belt of sandstone on the east (see map, PI. III). 

According to Mtze X1 the country rocks of this belt comprise (1) argil- 
laceous, sericitic and chloritic metamorphosed slates and crystalline 
schists; (2) sedimentary pre-Juratrias slates; and (3) ancient volcanic 
rhyolites, quartz porphyries, and pyro-clastic breccias, often sheared. To 

u Nitze, H. B. C, Bulletin No. 3, N. C. Geol. Survey, 1896, p. 28. 



THE VARIETIES OE BUILDING STONES. 55 

these may be added altered andesites ia and rocks belonging to more basic 
igneous types not yet differentiated. The general strike of the schistosity 
of the rocks composing the belt is northeast and southwest, with a steep 
northeast dip. 

Eocks of granitic composition have as yet been noted in only one 
county, comprised within the limits of the belt, namely, in Orange 
County; and these, so far as it is possible to judge from the exposures, 
seem to be of doubtful commercial value except for certain grades of 
rough work (see map, PL VI). 

The very extensive areas of volcanic rocks found within the limits of 
this belt would doubtless prove upon investigation to be in many cases of 
some commercial value. 

ORANGE COUNTY. 

True granites are found at several localities in Orange County as 
follows: Three miles southwest of Hillsboro, the county-seat, on the 
Hillsboro-Oaks road; one mile northeast of Chapel Hill on Bolans Creek 
where crossed by the Durham Eoad at the east margin of the crystalline 
rocks near the contact with the Triassic sandstones; 5 miles a few 
degrees west of south from Chapel Hill on the Pittsboro road ; 1J miles 
north of Chapel Hill along the road and on the north side of Brockers 
Creek; and 4 miles north of Chapel Hill and 150 yards east of the rail- 
road on the Brocker place. 

To the north of Chapel Hill outcrops of a hard and tough, massive 
compact, dark gray and medium to fine-textured igneous rock resembling 
diorite occur for some distance. The most important outcrops of the 
rock noted were at the long trestle on the east side of the railroad, three- 
quarters of a mile from the depot at Chapel Hill in large boulder ex- 
posures; on the Hillsboro road a half mile north of Chapel Hill; and 
Blackwood Mountain 5 miles north of Chapel Hill. These exposures 
show a variation in the rock from a medium and uniform dark gray color 
to that of a somewhat lighter shade of a " salt and pepper " appearance. 
Further variation in texture is from fine to medium grain. 

Blackwood is a conical peak which rises to a conspicuous elevation 
above the surrounding lowland. The rock shows the same variation in 
texture and color noted above. The feldspar in the coarser textured rock 
is a dull pink color. As yet no attempt has been made to quarry the rock 
in any of the exposures noted above but judging ^rom the character of 
the rock it would probably prove desirable for certain uses. The cost of 
quarrying this rock would probably exceed that of normal granites. 

12 Watson, Thomas L., Bulletin Geol. Soc. America, 1902, Vol. XIII, pp. 353-376. 



56 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

THE HILLSBORO AREA. 

On the Hillsboro-Oaks road, 3 miles southwest of Hillsboro, is an 
exposure of very hard, dull pink granite on the Gray farm. A small 
opening was made in the outcrop many years ago and a very limited 
quantity of the stone was quarried. The extent of the granite is un- 
known since only the single outcrop is found, which is of small size. 

It is a fine-textured granite composed apparently of quartz and feld- 
spar and very subordinate amount of a dark bisilicate showing in the 
hand specimen considerable alteration. Variation in color is from a 
pronounced pink to a very dull, dirty pinkish tone. It is much sheared, 
mashed and jointed in the exposure which renders the stone wholly un- 
suited for general building and other purposes requiring dimension stone. 
Two sets of joints intersect the rock striking N". 20° E., and N. 60° W. 
Several small veins or dikes not exceeding two inches in width penetrate 
the granite parallel with the set of joints striking N\ 20° E. The rock 
is apparently without grain or rift and is entirely useless as a building 
stone. 

Microscopical Examination. — Under the microscope a thin section of 
the rock showed a complexly interlocking aggregate of feldspar and 
quartz with a very subordinate amount of biotite, which is greatly altered. 
The feldspathic constituent comprises orthoclase, microcline and plagio- 
clase, very extensively altered and thickly crowded with dust-like par- 
ticles of red iron oxide. Occasional scattered grains of magnetite occur. 

THE CHAPEL HILL AREA. 

Boulder and ledge outcrops of granite are exposed along Bolans Creek 
where crossed by the Durham road, one mile northeast of Chapel Hill, 
near the contact of the crystalline rocks with the Triassic sandstones. 
The rock indicates much variation in texture from a very fine-grained 
irregularly porphyritic granite to a moderately coarse-grained even-granu- 
lar granite of a decided pink color. Eeddish pink feldspar, quartz and a 
small quantity of biotite are apparent to the unaided eye. The rock is 
entirely massive and is intersected by several sets of joints. No attempt 
has been made to quarry the stone and its marked variable texture would 
make it undesirable as a general building stone. 

On the Pittsboro road, 5 miles south of Chapel Hill, is an area sev- 
eral miles in width of a very fine and even-textured granite of faint pink- 
ish color. Exposures in the form of boulders are numerous over the 
area along the road. The rock yields a light gray nearly white sandy 
soil. 

In the hand specimens dull pink feldspar greatly predominates with a 



THE VARIETIES OF BUILDING STONES. 57 

little quartz and some biotite. No openings have been made in any of 
the exposures upon which to base an accurate judgment of its working 
qualities, but from the general appearance of the stone in the outcrops it 
is likely that the rock will prove to be of some commercial value. 

The outcrop on the Claytor place on the north side of Brockers 
Creek, one and a half miles north of Chapel Hill, shows more or less 
variation in texture and color, though the rock is usually dark gray and 
of a very fine texture. No statement can be made of the working quali- 
ties of the stone. 

Four miles north of Chapel Hill and 150 yards east of the railroad is 
an exposure on the Brocker place, of pinkish gray granite with porphy- 
ritic tendency, containing large laths of pink feldspar. It lacks uni- 
formity in both color and texture and for this reason it would not prove 
a very desirable stone for general building purposes. 



THE CABOLINA IGNEOUS BELT (THE MAIN GKANITE 

BELT). 

GENERAL DESCRIPTION OF THE BELT. 

This belt, shown on the accompanying map, Plate VI, occupies a 
nearly central position in the Carolina portion of the Piedmont plateau. 
It crosses the State in a general northeast-southwest course, beginning at 
a point to the east of Danville, Virginia, and extending southwestward 
into South Carolina. In width it will probably average from 15 to 50 
miles, and it is traversed for most of its length by the main line of the 
Southern Railway. The belt is further crossed by many of the principal 
railroads in the State at rather close intervals, which join the main line 
of the Southern at the principal towns of Greensboro, Salisbury and 
Charlotte. It is thus made one of the most accessible areas in the State. 

The limits of the belt are essentially those given by the State Geological 
Survey. Its. southeast extension can, as a rule, be traced with compara- 
tive readiness along an irregular line marking the contact with the belt 
of metamorphic slates and volcanics. On the northwest it is bounded by 
an extensive area of gneisses and schists of the western Piedmont region, 
and the line of differentiation between the two formations is less easily 
determined. From observations made during the present investigation, 
it has been determined that the limits should be extended somewhat 
farther westward in places. 



58 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

GENERAL GEOLOGIC RELATIONS. 

The area is composed principally of plutonic igneous rocks belonging to 
2 leading types, namely, granite and diorite. These may be massive 
or they may be more or less mashed and squeezed and schistose in struc- 
ture. They are penetrated by dikes of granite and diabase and other 
basic igneous intrusive types. Areas of variable schists are by no means 
absent but are often observed over the belt in many places forming the 
country rock. 

Dikes of granitic composition penetrate the rocks quite abundantly in 
places and are probably referable to apophyses given off from the larger 
granite masses. Sections exposed in the cuts along the Southern Kail- 
way and along the wagon roads in or near the towns of Concord, Salis- 
bury, Lexington and High Point best illustrate these granite dikes or 
apophyses. 

The granites are completely schistose in many places, one of the most 
noteworthy occurrences of which is the extensive granite-gneiss area on 
the Josey and adjoining places about 9 miles southwest of Salisbury 
in Eowan County. Perhaps the bulk of the granites within the Igneous 
Belt exhibit to some degree megascopic effects of pressure metamorphism 
in a more or less visible schistose structure. 

The area is further traversed by very many intersecting quartz veins of 
both large and small size. The abundance of the quartz veins, usually 
concealed by the deep covering of rock decay, is indicated by the almost 
innumerable angular fragments of the quartz strewn over the surface of 
the area. 

Two phases of the granite are prominently developed over many parts 
of the area, the porphyritic and the even-granular, which in nearly every 
case observed grades one into the other. A very pronounced zone of the 
porphyritic granite is traced in a northeasterly direction through a 
number of counties along the western margin of the belt. It is first 
observed to the southwest in Gaston County, in the vicinity of G-astonia, 
the county-seat, and passing northeastward through Iredell County, where 
large areas are exposed around Mooresville and Mount Mourne; thence 
to the west of Salisbury in Eowan County along the Yadkin Eiver in 
Davie County, and to the southeast of Winston-Salem in Forsyth 
County. To the west of Salisbury in Eowan County the porphyritic 
granite has a width of from 4 to 8 miles. In places the feldspar 
phenocrysts almost entirely fail, again reappearing within a short dis- 
tance in proportions equalling and at times exceeding the groundmass, 
in the ratio of the former to the latter. 

Wherever observed throughout this area the rock preserves nearly 



THE VARIETIES OF BUILDING STONES. 59 

constant characteristics. It is a coarse-grained, medium to dark gray 
biotite-porphyritic-granite. The feldspar phenocrysts are persistently 
marked by idiomorphic outlines of very ]arge size, measuring in extreme 
cases more than 2 inches in length by one inch across. They are 
usually white, though pink colored ones are not uncommon, and they 
nearly always contain more or less included biotite of the groundmass as 
large in size as that of the groundmass constituent. Twinning after the 
Carlsbad law is very frequent and the cleavage is pronounced. No 
orientation of the phenocrysts in the groundmass was strongly apparent. 

The rock is readily traced by its decay. The feldspar phenocrysts are 
abundantly scattered over the surface in a partially kaolinized condition 
and the individuals are often split into smaller fragments along the 
cleavage lines, with whole ones quite numerous. 

A second very prominent area of porphyritic granite is developed in 
Cabarrus County to the north and northwest of Concord, the county- 
seat, which is quite similar to that described above. To the southwest of 
Concord about 3^ miles is an area of coarse-grained augite-syenite, closely 
related to monazite, which possibly grades into even-granular and 
porphyritic granite on the northeast and southwest sides. A description 
of these rocks is given in detail under the respective counties in which 
they occur. 

Descriptions of the even-granular granites are best brought out under 
the individual areas. Hardly without exception, they are biotite granites 
of some shade of gray and they may vary from fine to coarse grain in 
texture. 

The diorites show considerable variation in composition, color and 
texture, features best described and brought out under the individual 
areas. So far as differentiation in the field was possible between the 
diorites and the granites, the contacts in the best exposures are always 
sharp and the two types of rock were not observed grading into each 
other. The sharp and distinct line between the two types is well drawn 
in the rocks exposed in the railroad cuts to the north and south of 
Woodleaf, a station on the Charlotte-Winston division of the Southern 
Railway, in the southwest corner of Eowan County. 

AGE RELATIONS OF THE ROCKS. 

From Nitze's 13 examination of the contact between the rocks of the 
igneous belt and those of the Carolina slate belt on the east, he inferred 
from the nature of the contact that the rocks of the Igneous Belt were 

13 Nitze. H. B. C, and Hanna, Geo. B., Gold Deposits of North Carolina, N. C. Geol. 
Survey, Bull. No. 3, 1896, p. 107. 



60 BUILDING AND OKNAMENTAL STONES OF NORTH CAROLINA. 

the younger. The few contacts between the rocks of these two belts 
examined by the writer tend to confirm Nitze's work. 

The so-called slate belt, including volcanics, constitutes Emmons 14 
Taconic and was later mapped as Huronian by Kerr. 13 

Mtze 16 assigned the rocks of this belt to pre-Cambrian age, pro- 
visionally to the Algonkian as defined by Van Hise." A study of some 
of the altered volcanics of both acid and basic types of Chatham and 
Orange counties in this belt, by the late Doctor George H. Williams, 18 lead 
him to refer them to a pre-Cambrian age. Eecent work by Watson 19 on 
a group of altered volcanics, meta-andesites, in the northern part of the 
belt showed the rocks to be pre-Cambrian in age. 

The igneous belt is limited on the west by an extensive belt of schists 
and gneisses which has been mapped by the State Geological Survey as 
probably Archaean. 20 The granites and diorites of the Igneous Belt 
exposed along the eastern border of the schist and gneiss belt are clearly 
younger in age than the latter rocks. Fairly good contacts between the 
rocks of the two belts were carefully noted in a number of places, and 
wherever these were observed the granites and diorites were found cutting 
across the schistosity of the schists and gneisses and otherwise showed 
their intrusive character into the gneiss-schist complex. 

As elsewhere shown in this report, the granites of the igneous belt 
are in part massive and in part schistose rocks and in places they exhibit 
further effects of pressure-metamorphism in crushing and fracturing. 
The pronounced schistose granites do not in all cases grade into those of 
massive structure. On this basis then the granites are inferred to be- 
long not to the same period of intrusion but rather to at least two sep- 
arate and distinct periods. Enough detailed work has not yet been done 
in this belt to completely differentiate and define the exact age relations 
of the rocks. Until this detailed work is accomplished, accompanied by 
accurate mapping, a definite statement cannot be made. 

Should the premises stated above prove correct and the ages assigned 
to the belt immediately on the east and west of the igneous belt be 
established, it would follow that the rock complex composing the Igneous 
Belt might in part be pre-Cambrian and in part of later age, Cambrian 
or even post-Cambrian. 

M Emmons, E., Geological Report, Midland Counties of North Carolina, 1856. 
is K errj W. C, Map accompanying Geology of North Carolina, 1875, Vol. I. 
10 Nitze, H. B. C, and Hanna, Geo. B., Op. Cit, p. 44. 

17 Van Hise, C. R., Correlation Papers, Bull. No. 86, U. S. Geol. Survey, p. 495. 
ls .Tourn. Geology, 1894, Vol. II, pp. 1-32. 

19 Watson, Thomas L., Bulletin Geol. Soc. America, 1902, Vol. XIII, pp. 353-376. 

20 See maps accompanying the various reports of the N. C. Geol. Survey. ■ 



THE VARIETIES OF BUILDING STONES. 61 

Likewise the dikes of basic igneous rocks penetrating the rock-complex 
of the igneous belt are not all of the same age but are to be referred to 
at least two separate periods of intrusion. Many of these dikes are 
correlated with similar ones intersecting Triassic sandstones to the east 
and hence are of the Juratrias age. Others which are noted penetrating 
the schistose rocks are likewise schistose to a more or less degree or 
otherwise altered, indicating their intrusion at a period prior to that of 
the metamorphism inducing schistosity in the enclosing rocks. That is, 
the disturbance affecting the enclosing rock similarly affected the inter- 
secting dikes of basic igneous material. This series of dikes is there- 
fore younger than the enclosing rocks but older than the period of dis- 
turbance inducing the schistosity. 

DESCRIPTION OF THE INDIVIDUAL GRANITE AREAS. 

Some of the largest and the most important granite areas in the State 
are included within the limits of the Carolina igneous belt. As a rule, 
the rocks composing the belt are deeply decayed but outcrops of the fresh 
or nearly fresh granite are somewhat frequent and they occur in every 
county comprised within the limits of the belt. The decay is, as a rule, 
characteristic of the underlying rocks from which it has been derived 
and the granites can usually be traced with considerable accuracy from 
the derived soil. 

Named in order from south to north the belt includes either the whole 
or a part of the following counties: Gaston, Mecklenburg, Cabarrus, 
Eowan, Iredell, Davidson, Davie, Forsyth, Guilford, Alamance, and Cas- 
well. With the exception of Caswell County, granite has been quarried 
to some extent in each of the counties named. Description of the 
individual areas is taken up by counties in the order here named. 

GASTON COUNTY. 

Numerous outcrops of granite occur over the central portion of Gaston 
County and a number of openings have been worked from time to time 
in the vicinity of Gastonia, the county-seat, to supply a local demand. 
The rock is usually deeply decayed yielding a pronounced characteristic 
light gray granitic soil by which it is readily traced over the surface. 
The nature of the decay indicates more the result of physical than of 
chemical forces, manifested in a goodly proportion of all the essential 
constituents in the fresh rock present in the decay. The biotite is nearly 
fresh and indicates but slight leaching from chemical action, which is 
further shown in the very slight discoloration of the decayed product 
6 



62 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

from the liberation of scant iron oxide. The feldspars have suffered 
more than the biotite and are very generally in an advanced stage of 
kaolinization. 

Both a porphyritic and an even-granular facies of the granite is indi- 
cated in the outcrops and in the openings of the fresh rock. These ex- 
posures extend from within the limits of the town of Gastonia in a north, 
northwest, and east direction for several miles. The rock is a biotite 
granite of light to dark gray in color and varies from fine to medium 
coarse-grained in texture. With but few exceptions, a pronounced por- 
phyritic tendency is indicated over most of the area. 

Beginning at Gastonia and extending for a distance of about 2-| 
miles east-northeast along the Gastonia-Charlotte macadam road is 
a belt of gray coarse-grained porphyritic granite. The feldspars make 
up at least 50 per cent of the rock mass and, in places, more. The pheno- 
crysts are white opaque and very large, measuring in extreme cases more 
than an inch in length. They are usually flat-tabular, idiomorphic in 
outline and contain biotite inclusions of the groundmass. A tendency 
toward orientation in the phenocrysts is exhibited in places. The rock is 
exposed in shallow cuts along the road and in an advanced stage of decay 
similar in character to that described above on page 58. The pheno- 
crysts observe essentially the same position and characteristics in the 
decay as in the fresh rock, except that they are dull in lustre and largely 
altered to kaolin. 

About 2-J miles east-northeast of Gastonia the porphyritic granite is 
in contact with a body of micaceous schists which are much crushed and 
closely jointed in places. The rocks are deeply decayed at the contact 
and no fresh exposures of them are to be found nearby but so far as 
could be made out, the granite is probably the younger rock intrusive 
into the schist. 

THE GASTONIA GRANITE AREA. 

North of Gastonia about \ mile beyond the incorporate Kmits, 
2 small openings were made several years ago to obtain stone for local 
use as sills in the cotton mills in the town and as bases for monuments. 
The openings are near together in flat ledge exposures along a small 
stream fed from a nearby spring. The rock is a biotite granite of medium 
texture and gray color. It is fairly uniform in both color and texture 
and is of good quality. In places it is decayed to a depth of from 6 to 8 
feet; the feldspars are partially kaolinized while the biotite manifests 
scarcely any alteration. 



THE VARIETIES OF BUILDING STONES. 63 

Two sets of joints striking N". 60°-70° W., and N. 40°-60° B., cut the 
granite at sufficiently spaced intervals to admit of large size blocks being 
quarried. Several quartz-feldspar veins free from mica and not exceed- 
ing 1 to 2 inches in width were noted in the openings. In addition to 
these occasional irregularly rounded segregation areas of biotite, nearly 
black in color and 1 to 3 inches in diameter, occur. 

Within the western limits of Gastonia flat-surface masses of the same 
granite are exposed. A single small opening has been made and a few 
feet of the surface stone quarried. Jointing is in two directions approxi- 
mately tf.-S., and E.-W. 

About If miles north of Gastonia several small openings have been 
worked recently, immediately along the Gastonia-Dallas macadam road. 
The rock is a biotite granite in all respects similar to that opened in 
the eastern and northern limits of the town, except that it is finer in 
texture. Joints penetrate in two directions, namely, rT.-S., and ET. 
60° -70° W. The small amount of the stone quarried has been used for 
macadam purposes on the road along which it occurs. 

Microscopical Examination. — Slides cut from hand specimens of the 
granite opened in the north and the east limits of the town of Gastonia, 
show a somewhat coarser textured granite than that opened If miles 
north of the town, on the macadam road. Also more biotite is indicated 
in the thin sections of the latter rock, which in the hand specimen is 
correspondingly darker in color. The same features are developed 
megascopically in the granite of the two localities. 

The rock is a biotite granite in which the potash feldspars, orthoclase 
and microcline, are present in nearly equal amount, except in the rock 
from the opening in the eastern limits of the town, the thin section of 
which shows orthoclase in excess of microcline. In several of the sec- 
tions plagioclase failed entirely, while in the others only a few scattered 
finely striated grains were noted. Micrographic intergrowths of quartz 
and feldspar are rather freely developed in all the sections, indicating 
the overlapping of the periods of crystallization of the two minerals. 
Micropoikilitic structure and microperthitic intergrowths are indicated 
in each one of the sections. 

Much secondary museovite derived largely from the alteration of the 
feldspars is indicated in the thin sections in the form of both large 
shreds and minute scales in association with kaolin. Biotite is of the 
usual kind and is largely altered to chlorite, some epidote, and iron 
oxide. The usual microscopic inclusions of apatite and zircon occur. 



64 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

THE BELL-PEYSOUR OPENINGS. 

About 2J miles west of north from Gastonia and one-half mile 
west of the Gastonia-D alias macadam road, is a granite ridge about 
600 yards long trending about N". 30° E., and with an elevation of some 40 
to 50 feet above the adjacent stream. A light gray variable textured 
biotite granite outcrops as flat-surface masses and boulders over the top 
of the ridge. At the south end and on top of the ridge the first raise 
over a large flat surface exposure of the granite was being worked up in 
August, 1903. The rock was being worked into shape for building an 
engine bed in one of the Gastonia cotton mills. The granite in this 
opening varies from a rather coarse to medium fine-textured rock with a 
like variation in color noted, according to the amount of biotite present. 
The entire raise indicated partially altered stone but with the next raise 
fresh granite may be expected. No veins are present in the granite and 
only one set of joints was observed penetrating the rock, striking N". 20° 
E. This opening is on the Bell place. 

Microscopical Examination. — A thin section prepared from a hand 
specimen of the granite from the Bell opening indicated, microscopically, 
a larger proportion of microcline than orthoclase and scant plagioclase. 
The usual occurrence of microperthite is noted. Micrographic inter- 
growths of quartz and feldspar are abundantly distributed through the 
slide. Biotite is greatly altered to chlorite and some epidote ; and much 
muscovite, derived principally from the alteration of the feldspathic con- 
stituent, is present. The usual microscopical accessories occur. 

The rock is essentially the same as that described above within the 
limits of the town of Gastonia, except that its texture and color are less 
uniform. 

About 200 yards north of the Bell opening and on top of the same 
ridge a small opening was made some 12 or more years ago on the 
Rhodes place (known as the Peysour quarry) in a similar but smaller ex- 
posure of the granite. The rock is essentially the same as that described 
from the Bell opening except that a few small black segregation areas of 
biotite are present in places. A porphyritic tendency among the feld- 
spathic constituent is developed in the granite of both openings. The few 
rock quarried from the Peysour opening are reported to have been used in 
part for trimmings in the court-house building at Dallas, and in part for 
monument bases. 

Microscopical Examination. — Under the microscope a thin section of 
the granite from this opening indicates a finer textured rock than that 
from the Bell opening. Otherwise the mineral constituents of the two 



THE VARIETIES OF BUILDING STONES. 65 

granites are identical. Micrographic structure seems more abundant 
in the thin section of this rock than in the former one. Alteration pro- 
ducts of the biotite are the same for the two rocks. 

THE JENKINS QUAERY. 

Two to 2| miles N". 60° W. of Gastonia, two openings one-quarter 
of a mile apart in an east-west direction, have been made in a 
porphyritic biotite-granite of medium-gray color and texture. Ait the 
west opening, which is the largest one, the ^exposure is crossed by a tiny 
stream. The rock is split into curbing 10 to 12 feet long for which 
it is principally used, although a few monument bases are reported to 
have been quarried. The rock indicates more or less of a schistose struc- 
ture in a N". 10° E. direction along which it readily splits. Two sets of 
joints, spaced at wide intervals, cut the granite-mass striking N". 20° -30° 
E., and N. 80° W. 

The feldspar phenocrysts are rather sparingly distributed through the 
rock; both idiomorphic and allotriomorphic ones appear, the former ex- 
hibiting flat-tabular outlines and measuring two inches long by one- 
quarter to one-half inch across in the largest ones. The phenocrysts are 
further characterized by inclusions of large flecks or plates of the ground- 
mass biotite, and they have a faint pinkish tone. 

Microscopical Examination. — Under the microscope a thin section of 
this granite shows the biotite arranged along somewhat parallel lines in 
the direction of the longer axis of the individual shreds, with some 
granulation from pressure effects of the other minerals noted. The min- 
eral constituents are the same and they occur in about the same order of 
abundance as in the other granites noted above from Gaston County. 
Considerable finely striated plagioclase in long laths is distributed 
through the slide. Chlorite, a colorless mica, iron oxide, and some epi- 
dote occur as alteration products derived from the biotite. The large 
feldspar individuals show the micropoikilitic structure. The phenocrysts 
consist entirely of potash feldspar. 

The granite on the Jenkins place is easy to quarry and it is an excellent 
stone for the uses made of it. 

THE HOPE QUARRY. 

About 3 miles northwest of Belmont, a station on the main line of 
the Southern Eailway, exposures of a very' desirable granite occur on both 
sides of a small stream. A small quantity of the stone has been quarried 
in a number of places. Eecently an opening has been made in a flat- 



66 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

surface outcrop of the rock on the northwest side of the Gaston-Charlotte 
road and about 200 yards distant from it. 

The rock is a medium-textured, light gray with a pinkish tone biotite- 
granite and completely massive in structure. It bears a slight resem- 
blance to the granite quarried at Dunns Mountain in Eowan County 
Jointing is not conspicuous in the rock. Only one set of planes were 
observed, which showed a strike of N". 20° W. The joint-planes show 
slickensided surfaces. No veins nor injurious minerals occur in the rock. 
Very small and scattered segregated areas of biotite are developed in 
places through the rock, buir these are not of large enough size nor suf- 
ficiently numerous to in anywise injure the granite. 

The feldspars are colored a very faint pinkish tone, which imparts the 
barest mixed gray and pink color to the rock. It is a hard granite, quite 
lively in appearance and of uniform color and texture, and it should 
prove a very desirable stone for general building purposes. 

Microscopical Examination. — Microscopically, the rock is a biotite 
granite in which orthoclase is in excess of microcline. Much finely 
striated acid plagioclase is distributed through the slide. Microperthite 
is in usual amount and Carlsbad twinning is observed to some extent 
among the potash feldspars. The feldspars are distributed through the 
section in large partially idiomorphic crystals, usually much altered into 
kaolin and small scales of muscovite. Biotite shows the usual alteration 
into chlorite and some epidote and other secondary products not posi- 
tively identified. The rock as a whole is some coarser in texture than 
the other granites occurring in Gaston County and described above. 

The granite mass is quite an extensive one, exposed over the area in 
the nature of large boulders and flat-surface masses. The Gaston-Char- 
lotte road leading to Belmont Station traverses the area for a distance 
of not less than one mile. As a rule, the larger flat exposures require 
little or no stripping before working, there being in many cases practi- 
cally no sap on the rock. 

The granite quarried up to the present time has been used principally 
for foundations, sills and trimmings in buildings in the city of Charlotte, 
and for the same purpose in one of the buildings of Saint Mary's College, 
near Belmont. 

Dikes of Basic Igneous Rocks. 

At only 2 points within the granite area of Gaston County has dike 
material been observed. About 1-J- miles northeast of Lowell Station 
on the main line of the Southern Railway, a dike of dioritic material 
crosses the Gastonia-Charlotte road. 'No fresh material could be 



THE VARIETIES OF BUILDING STONES. 67 

obtained at this point. Again to the southeast of Gastonia, near the 
large cotton mill, scattered boulders of diabase were noted along the road 
but they could not be located in place. These evidently indicate a dike 
of diabase nearby. 

MECKLENBURG COUNTY. 

Mecklenburg County contains an abundance of igneous rocks ranging 
in composition from the most acid to the most basic kinds. Granites 
and quartz-porphyry (leopardite) among the acid, and diabase, diorite, 
lamprophyre and peridotites among the basic rocks are the principal types 
represented. 

Although granite occurs very generally over the County, comparatively 
few quarries have yet been opened. For convenience of description the 
granite of this County may be treated under the following areas: The 
Charlotte area; The Morning Glade Church area; and, the Davidson 
area. 

THE CHARLOTTE GRANITE AREA. 

Under this heading are included all known granites within a radius of 
5 or 6 miles of the city of Charlotte. Openings have been worked 
within the city limits of Charlotte; at several places about 4 miles east 
of the city; at several places 5 and. 6 miles south of Charlotte; just beyond 
the southeast limits of the city; and at Belmont Springs, about 1J miles 
east of the public square in Charlotte. 

THE CITY QUAREY. 

Near the freight depot in the southeast quarter of the city of Charlotte 
an extensive opening in a much crushed granite has been worked for 
many years to supply stone principally for macadamizing the streets, and 
for ballast. As nearly as could be determined, the opening is 350 feet by 
400 feet at the top and has been worked to an average depth of 50 feet. 
The rock is too much crushed and jointed, and too variable in color and 
texture, to be used for any purpose except as road material and ballast. 
During August, 1903, stone was being quarried for macadamizing the 
city streets, for which the granite seems admirably suited. A crusher 
was in operation at the quarry for crushing and sizing the stone. Ee- 
sults of tests of this rock for road material are given on p. 266. 

The rock is a hard and close-textured biotite granite, the average phase 
of which is fine-textured and of bluish gray color, manifesting in places 
much epidotization. It is penetrated at close intervals by 2 principal 



68 BUILDING AND OKNAMENTAL STONES OF NOETH CAEOLINA. 

sets of joints, which strike N". 40° E., and K 35°-50° W., the surfaces of 
which are usually slickensided (see Fig. A, PI. VII). In addition to 
the joints the rock is penetrated by a series of dark greenish, fine-grained 
schistose diabase dikes which range from 12 inches to several feet 
across. Quite a number of these dikes are exposed in the quarry cutting 
the rock at irregular intervals and coincident with the jointing whose 
strike is N". 40° E. The contacts between the granite and the basic 
eruptive are always clean cut and sharp (Fig. B, PL VII). 

Microscopical Examination. — Under the microscope a thin section of 
the rock shows a biotite granite of a fine textured complexly interlocking 
aggregate of feldspar and quartz. Potash feldspars, orthoclase and mi- 
crocline, and mieroperthitic intergrowths, with very little plagioclase 
compose the feldspathic constituent. The biotite is irregularly distrib- 
uted through the section in small shreds and largely altered. A few 
scattered grains of magnetite occur and the effects of dynamic-metamor- 
phism are distinctly manifest. 

A thin section of a specimen from one of the dikes of basic eruptive 
rock penetrating the granite in this quarry shows under the microscope 
a uralitic or altered diabase of very fine texture. The augite is altered 
to the usual form of hornblende and a little quartz is distributed through 
the section. 

THE ORDERS 'QUARRY. 

Just beyond the southeastern limits of the city of Charlotte, 2 small 
openings, made near together, have recently been worked for road ma- 
cadam. The rock is quite similar to that described above from the City 
quarry. It varies in texture and composition, is bluish to greenish gray 
in color and is much crushed and intersected by close jointing. The 
strike of the joint-planes is N". 10° W., and N. 60° W., and their surfaces 
are typically slickensided. Much epidotization is in evidence in the 
rock at the openings. The rock can only be used for macadam and bal- 
last, for which it seems well suited. 

THE SNELL OPENING. 

Four miles east of Charlotte, on the south side of the Charlotte- 
Monroe road on the Seaboard Air Line Eailway, some granite has been 
quarried to a limited extent for road purposes. The rock outcrops in 
and along a small stream. It is a biotite-granite, quite variable in com- 
position and texture, and is penetrated by a number of diabase dikes 
striking 1ST.-S., KT. 25° W., and N. 10° E. Both the enclosing granite 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE VII 




A. CITY QUARRY, CHARLOTTE, N. C, SHOWING DEVELOPMENT OF JOINTS PENETRATING THE GRANITE. 




B. DIABASE DIKE PENETRATING GRANITE AT CITY QUARRY, CHARLOTTE, N. C. 



THE VARIETIES OF BUILDING STONES. 69 

and the basic dike rocks are greatly crashed from pressure-metamorphism 
and are otherwise rendered schistose. The rock can only be used for 
macadam and ballast. 

THE DUNN QUARRY. 

About one mile west of the Snell opening and on the same stream, 2 
small openings have been made in outcrops of a biotite granite, which is 
in every respect the same as that described above on the Snell place. The 
stone quarried is reported to have been used for macadam. 

Two parallel dikes of diabase about 50 paces apart, trending N". 20° 
E., and less than 12 feet wide, intersect the crashed granite in this 
quarry. On the opposite side of the stream next to Mrs. Dunn's house, 
are outcrops of a dark holocrystalline eruptive which may possibly prove 
to be a f acies of the granite. 

THE SMITH QUARRY. 

About 5 miles south of Charlotte and a quarter of a mile west of 
the Nation Ford road, boulder outcrops of a hornblende-bio tite granite 
are exposed over an area of less than a dozen acres in extent. A number 
of small openings have been made in different places and some of the 
largest boulders have been partially worked off. The first quarrying 
was done some years ago when millstones are reported to have been 
quarried and used in the early ore-mills of the gold mines in Mecklenburg 
and the adjoining counties. 

The rock is a medium-textured, uniformly blue-gray, hornblende-biotite 
granite of most pleasing appearance. Small segregations or bunches of 
the ferro-magnesian constituent, principally biotite, are distributed 
through some portions of the rock, but they are not sufficiently numerous 
nor large enough to detract from the good qualities of the stone. Occa- 
sional pyrite crystals are distributed through the rock, but this constituent 
does not appear in quantities large enough to in any wise injure the stone. 
The rock is perfectly massive in structure and blocks of almost any size 
can be quarried. It is a very desirable stone and it should prove to be 
admirably adapted to monumental purposes. 

In addition to the mill stones mentioned above, the rock has been used 
for monumental stock and for building purposes in the city of Charlotte. 
The stone used in some of the older buildings in Charlotte show no vis- 
ible effects of weathering and it is apparently quite as fresh as when it 
was first quarried. The rock is susceptible of a high polish and a num- 
ber of monuments in the city cemetery in Charlotte are reported to have 
been fashioned from stone quarried at this locality. 



70 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Microscopical Examination. — Several thin sections cut from the rock 
at this locality showed microscopically, a hornblende-biotite-granite of 
medium texture, composed of the principal minerals feldspar, quartz, 
hornblende, and biotite with some minor accessories, including much 
titaniferous magnetite. Large stout laths of striated plagioclase, consid- 
erably altered, are freely distributed through the section with the prin- 
cipal potash feldspars. Biotite and hornblende show the usual alteration 
products, the principal one of which is chlorite. Much titaniferous 
magnetite occurs. 

THE KIRK PATRICK OPENING. 

About one mile southeast of the Smith Quarry, described above, on 
King's branch and about 6 miles south of Charlotte and a quarter of a 
mile southeast of the Nation Ford road, boulder outcrops of the same 
granite' as that described from the Smith Quarry are exposed. One small 
opening was made several years ago to obtain rock for road purposes. In 
composition, texture and color the rock is identical with that quarried on 
the Smith place. It is, however, filled with segregations or bunches of 
the ferro-magnesian minerals of black color and fine grain, which vary 
in size from an inch to 6 inches and more in diameter. These segrega- 
tions are so numerous in the rock at this point as to render the stone 
unfit for any purpose save that of rough grades of work. 

In outline the segregation areas range from roughly oval-shaped forms 
to those very much elongated and they apparently observe orientation 
through the rock in the direction more or less parallel to their longer 
axis. Sharp contacts are observed between the segregation and the en- 
closing granite. A single slickensided joint-surface was noted. 

THE CALDWELL PLACE. 

About 3£ miles northeast of Charlotte and about 100 paces 
to the right of the Concord road, a small opening has been made in 
an exposure of medium-textured gray biotite-granite. The opening is 
in a small ledge outcrop along a small stream. Joints intersect the 
rock in a general N. 40° W. direction, and it is further intersected by 
numerous thin seams and veins of pegmatitic composition. Several large 
inclusions of the country rock are exposed in the granite-mass. 

Quartz-Porphyry (Leopardite) . 

The earliest published accounts of the aptly named leopardite in North 
Carolina appear in the American Journal of Science for the years 1853 
and 1862. As early as the year 1853, Hunter, in a paper entitled " Notes 



THE VARIETIES OF BUILDING STONES. 71 

on the Rarer Minerals and New Localities in Western North Carolina" 
gives a brief description of the leopardite occurring east of Charlotte in 
Mecklenburg County, North Carolina. He says :" 

" It is noticed by Professor Shepard, under the head of feldspar, as the 
" Leopard Stone of Charlotte, North Carolina." 

In this paper the author refers to a second locality where leopardite 
has been found in the State, namely, in Lincoln County. 

In 1862 Doctor F. A. Genth, under the caption " Contributions to 
Mineralogy," " published in the same journal, describes the leopardite as 
a true porphyry and gives the results of a microscopical examination to- 
gether with a chemical analysis. Doctor Genth mentions a third locality 
in North Carolina where leopardite is found, namely, near the Steele 
mine, in Montgomery County. 

In addition to these, the rock near Charlotte has been more recently 
noted by Merrill " and Lewis. 24 The former in his treatise on " Stones 
for Building and Decoration," where, after briefly describing the rock, a 
statement is made of its economic value. In connection with his work 
on Building Stones of North Carolina, Lewis visited the locality east of 
Charlotte where the leopardite occurs and was probably the first to note 
its true occurrence. 

Location and Description. — The leopardite is exposed in a number of 
outcrops at Belmont Springs, 1J to If miles east of Charlotte. 
Beginning at a point on top of the hill, about 100 to 150 
yards above the spring, the rock can be traced for a distance of from 
one-quarter to one-half mile in a N. 30° E. direction on the Phifer 
place, where the largest opening has been made. The leopardite forms 
a true dike intersecting a biotite-granite of much the same character 
as that described above at the Charlotte City quarry and on the Or- 
ders place. So far as it was possible to determine, the dike nowhere 
exceeds 25 feet in width and in places it is less. The contact with the 
enclosing granite is sharply denned at the opening on the Phifer place to 
the northeast of the spring. 

In the fresh specimens the rock is nearly pure white, tinged the very 
faintest greenish tone in places, and penetrated by long parallel streaks 
or pencils of a dead black color. When the rock is broken at right angles 

21 Hunter, C. L., Notices of the Rarer Minerals and New Localities in Western North 
Carolina, Silliman's Journal, 1853 (2 S.), Vol. XV, p. 377. 

22 Genth, F. A., Contributions to Mineralogy, Amer. Journ. Science, 1862 (2 S.), 
Vol. XXXIII, pp. 197-198. 

^Merrill, Geo. P., Stones for Building and Decoration, New York, 1897, 2d Edition, 
pp. 272-273. 

24 Lewis, J. V., Notes on Building and Ornamental Stone, 1st Biennial Report, N. C. 
Geol. Survey, 1893, p. 102. 



72 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

to these, the surface appears spotted with rounded irregular black points, 
ranging in size up to a half inch in diameter (PI. VIII, Fig. A). A 
section cut parallel with the direction of the pencils presents a surface 
streaked with long somewhat irregular though roughly parallel black 
lines, assuming at times complete dendritic or fern-like forms (PI. VIII, 
Fig. B.). At times the roundish points are somewhat irregular and are 
only partially developed, presenting a surface which roughly resembles 
the cuneiform surface of graphic granite. The pencils may be crowded 
uniformly close together over a surface as shown in Fig. A, PL VIII, or 
they may be entirely absent from some areas and irregularly distributed 
at wide intervals over others. Indeed the black pencils are reported to 
decrease and finally disappear in the rock as the dike is traced northward. 
Every outcrop and specimen of the rock, however, that was examined 
contained them. These black streaks or pencils are composed of the 
oxides of iron and manganese. 

The rock is a dense and compact cryptocrystalline quartz-porphyry 
which breaks with a conchoidal fracture, and it is intensely hard and 
tough. Good specimens of it are well nigh impossible to obtain with 
the hammer but requires a shot to break them. Minute quartz crystals of 
perfect doubly terminated pyramidal faces are disseminated through the 
matrix. These are not abundant and are apt to be over-looked unless 
the rock is carefully scrutinized, but they are always present and are of 
both white and dark smoky vitreous quartz. 

Microscopical Examination. 25 — Microscopic study of sections of the 
rock shows an exceeding finely crystalline aggregate or groundmass of 
completely interlocking quartz and feldspar, through which is distributed 
a large proportion of irregular minute shreds of a colorless mica, probably 
muscovite. The mica has its greatest development along the sutures of 
the quartz and feldspar and is often found penetrating both of these min- 
erals. It occurs in partially radiate tuft-like forms and in single and 
intergrown shreds. 

Feldspar is the most abundant constituent in the rock and, so far as 
could be determined, it is composed of both potash and plagioclase species. 
Occasional grains of microcline are recognized which show the character- 
istic microcline twinning. Optical tests show the plagioclase to be albite, 
some of which exhibits polysynthic twinning. Prismatic habit is 
strongly developed in much of the plagioclase, and the entire feldspar 
content is very generally clouded by innumerable inclusions, the exact 
nature of which it was not posssible to determine. 

25 The Leopardite (Quartz Porphyry) of North Carolina, hy Thomas L. Watson, Jour- 
nal of Geology, 1904, Vol. XII, pp. 215-224. 



.N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE VIII 




pm **> *m T ? 



* --T.tVtU??.^' 






. •«# •'A* #, 



A. PHOTOGRAPH OF FRESH SURFACE OF LECPARDITE SHOWING THE STONE WHEN BROKEN AT RIGHT 
ANGLES TO THE LONG PARALLEL STREAKS OR PENCILS OF A DEAD BLACK COLOR. 




PHOTOGRAPH OF A SECTION OF THE LEOPARDITE CUT PARALLEL WITH THE DIRECTION OF THE 

FENCILS. 



THE VARIETIES OF BUILDING STONES. 73 

Quartz is the next most abundant mineral in the rock, forming minute 
irregular interlocking grains. Much of it is intergrown with the feldspar 
in micrographic structure, forming more or less rounded disk-like areas, 
some of which show quite distinctly under cross nicols a somewhat spheru- 
litic tendency of distinct radiate structure. When they form complete 
spheres, which is rarely the case, they usually exhibit somewhat irregular 
ragged peripheries, and further show usually between cross nicols a very 
indefinite black cross. Other of the areas have much the same appear- 
ance as the similar structure in the normal granite. 

Phenocrysts of both idiomorphic quartz and feldspar are distributed at 
wide intervals through the finely crystalline quartz-feldspar groundmass. 
In the hand specimens these are apt to be over-looked unless the rock is 
very carefully scrutinized. Under the microscope the phenocrysts ap- 
pear as squarish sections of quartz and somewhat broad lath-shaped forms 
of feldspar. Both orthoclase and a broadly twinned acid plagioelase are 
developed porphyritically. Unlike the groundmass feldspar the porphy- 
ritic feldspars usually show more or less alteration into kaolin and musco- 
vite. 

Several of the thin sections were so cut as to include areas of the black 
pencils shown in the hand specimens. These are distinguished microscop- 
ically from the white portions of the groundmass only by a distinct 
medium to dark yellowish brown staining which closely resembles that of 
limonite, such as is often observed in the partial leaching of an iron- 
bearing mineral in igneous rocks. No definite source from which this 
staining was derived was entirely indicated in any of the sections, but 
that they represent percolation of iron and manganese solutions through 
the rock scarcely admits of reasonable doubt. Why the definite arrange- 
ment into long pencils and dendritic forms manifested megascopically, 
evidence is again lacking, for the textural conditions and relations of 
the minerals in the areas are precisely the same as for other portions of 
the rock. Microscopic study suggests the probability that the penciled 
structure of the rock will prove not to be uniform throughout the entire 
rock-mass, but probably characterizes only certain portions of it. 

The dust-like inclusions in the feldspars mentioned above may possibly 
prove to be the free oxides of iron and manganese from which the stand- 
ing is derived forming the areas, but the examination of the slides does 
not seem to indicate such a source. 

The following is a chemical analysis of carefully selected pieces of 
the leopardite matrix made by Doctor F. A. Genth : as 

26 Genth, F. A., Amer. Jo.urn. Sci., 1862 (2 S.), Vol. XXXIII, p. 198. 



74 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

Analysis of Leopardite. 

Si0 2 : 75.92 

A1 2 3 14.47 

Fe 2 3 0.88 

MgO 0.09 

CaO 0.02 

Na 2 4.98 

K 2 4.01 

Ignition 0.64 

Total 100.01 

The most noteworthy features of the analysis are the nearly complete 
absence of lime and the slightly increased amount of soda over potash, 
circumstances which would seemingly indicate the lack of any one of the 
lime-bearing plagioclase species and that much of the feldspar is com- 
posed of anorthoclase and orthoclase. This conclusion is fully confirmed 
by the microscopic study. 

In the weathered outcrops, which are still hard and firm rock, the 
matrix presents an opaque lusterless dead chalk-like whiteness and the 
pencils are bleached to some extent, and changed from a black to a 
slightly reddish-brown color. 

The rock is without definite rift but it shows some jointing which fact, 
coupled with its exceeding hardness and toughness, would make the stone 
an expensive one to quarry. The slight openings already made were to 
obtain stone for local use and to some extent for the procuring of museum 
specimens. The rock is susceptible of an excellent polish and it could be 
used to splendid effect in inlaid work. Specimens in both the rough and 
polished state, including a carved figure of a leopard, are on exhibit in 
the building stone collection in the State Museum at Raleigh. The stone 
is probably too brittle to yield good results in carving. It has been used 
in a very small way locally for curbing, steps and sills. 



THE MORNING GLADE CHURCH AREA. 

This name is given to a granite area in the vicinity of Morning Glade 
Church on the Fayetteville Road, a few miles east of the Mecklenburg- 
Cabarrus county line and about 4 miles east of south of Newells, a 
station on the main line of the Southern Railway. The area is further 
located about 10 miles slightly north of east from Charlotte. The 
granite is best exposed on the Cross place, in the form of immense boulder 
outcrops, several of which have been split and a few stone quarried for 
bridge work. 



THE VARIETIES OF BUILDING STONES. 75 



THE CROSS PLACE. 



About 10 miles east from Charlotte and near the Cross dwelling house, 
are large boulder outcrops of a light gray biotite-granite exposed over a 
considerable area. The largest boulders will measure from 20 to 30 feet 
high and they are proportionately large in other dimensions. One of the 
largest boulders has been split and nearly worked up into stone for piers 
in the construction of a bridge nearby on the Fayetteville road. 

The rock is a medium-textured massive granite but, as indicated from 
the large boulder that is nearly worked up, is partially decayed through- 
out. The feldspars are more or less kaolinized and the biotite shows 
alteration and leaching in the staining of the decayed rock from the 
liberated iron oxide. In the fresher portions of the rock the biotite has 
apparently suffered more from decay than the feldspars. Some of the 
feldspars are nearly entirely fresh while the biotite in the same areas of 
the rock shows considerable leaching of the liberated iron oxide, dis- 
coloring the rock. The fresh granite should be encountered at a very 
moderate depth below the decay, which judging from the character of 
the bouldeirs should prove to be a desirable stone for general building 
purposes. 

The bouldery outcrops form an elevated ridge back some little distance 
from a small stream and at some elevation above the water level. The 
location is a very favorable one for quarrying. 

THE DAVIDSON GRANITE AREA. 

This area is named for the principal town, Davidson, occurring within 
the limits of the area. The town is located on the Charlotte-Winston 
Branch of the Southern Eailway, in the extreme northern part of Meck- 
lenburg County and only a few miles south of the Iredell County line. 
The area includes all the granites occurring in the northern portion of 
Mecklenburg County. It extends northward into Iredell County, the 
limits of which include nearly the entire southern portion of the County, 
and to some distance north of Mooresville. It should more properly 
be designated the Davidson-Mooresville area, since no geographic boun- 
dary can be drawn between the 2 counties that would separate the area, 
but since the method of treatment in this report is by counties, it is 
thought best to divide it into the Davidson area in Mecklenburg County, 
and the Mooresville area in Iredell County. 

One distinction can be drawn, however, between the subdivisions of 
the area here made, which is that in the Mooresville part of the area, 
the main body of the granite is typically porphyritic, identical' with that 



76 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

described to the north of G-astonia, in Gaston County. Over the David- 
son area to the south in Mecklenburg County, the rock is an even-granu- 
lar granite, hornblende-bearing in places, a feature not observed in the 
northern part of the area around Mooresville. 

Numerous small openings to the east, south, and southwest of David- 
son have been made at different times in Mecklenburg County to obtain 
stone for local use, but no regular quarries have been worked. 

One-half mile east of Davidson, immediately on the north side of the 
macadam road, a few partially decayed granite boulders exposed in the 
residual decay of the granite have been worked recently for road material. 
The opening extends a slight depth below the boulders into the decayed 
rock. The decay is quite deep and is of the characteristic gray and red 
colors shown in the earlier and more advanced stages of granite-weather- 
ing. 

The rock is a fine textured, light gray, biotite-granite, which can be 
utilized to advantage in many of the lower grades of work in which gran- 
ite is used. 

Microscopical Examination. — Under the microscope a thin section of 
the rock showed a biotite granite of medium-fine texture, composed of an 
aggregate of potash and some plagioclase feldspars, quartz, and biotite. 
Biotite shows the usual alteration. Several small grains of pyrite were 
scattered through the section, but pyrite was not observed by the unaided 
eye in the hand specimen. Effects of crushing and recrystallization from 
dynamic forces are indicated. A few areas of micrographic intergrowths 
of quartz and feldspar are shown and micropoikilitic structure is more or 
less well developed. 

A short distance below the opening, exposed along the roadside, is a 
small dike of diabase penetrating the granite. The exposure is in a sec- 
tion of granite decay. 

THE CALDWELL PLACE. 

One mile east of Davidson and about a quarter of a mile south of the 
macadam road are somewhat extensive boulder and ledge outcrops of a 
very desirable granite, exposed along a small stream just below the Cald- 
well dwelling-house. Tbe rock is exposed over the wooded slopes on the 
2 sides of the stream and extends over not less than 50 to 60 acres 
of surface. Some of the surface stone was quarried many years ago in 
an exposure of the rock just above the stream and used for foundations 
in several of the buildings of Davidson College. 

The rock is a biotite-bearing hornblende-granite of medium texture 
and medium-gray color, intensely hard and tough and lively in appear- 



THE VARIETIES OF BUILDING STONES. 77 

ance. After seme testing it was reported that the rock was found to be 
too hard for crushing and mixing in the rock-crushers. The hornblende 
is greenish-black in color and it is distributed through the rock in the 
form of irregular grains and lath-shaped idiomorphic crystals, measuring 
in extreme cases as much as 1^ inches long by a quarter of an inch wide. 

Two sets of joint-planes intersect the granite striking N. 20° W., and 
N. 70° E. Many areas of hornblende-biotite segregations of dark color 
and irregular outline measuring from 2 to 10 inches long by 1 to 3 
inches across, are quite freely distributed through the rock in places. 
Good dimension stone, however, free from the dark segregation areas can 
be quarried. Altogether the rock is a pleasing one in both color and 
texture which in connection with its other good qualities make it an 
admirably suited stone for general building and other purposes. 

Microscopical Examination. — Thin sections of the rock show striated 
plagioclase in excess of the potash species with beautiful zonary structure 
developed in them: quartz, biotite, hornblende, and some magnetite. 
Plagioclase is distributed through the sections in large stout laths. No 
injurious minerals were noted in the thin sections. A little chlorite and 
epidote occur as alteration products. 

THE HARRIET SLOAN MILL PLACE. 

On the west fork of Eocky Eiver, about 5 miles east of Davidson 
are immensr- boulder outcrops of a medium fine-textured, gray, biotite- 
granite exposed partly in Mecklenburg and partly in Cabarrus counties. 
The exposures are traced for some distance on both sides of the stream, 
but on the east side in Cabarrus County, the boulders are of huge dimen- 
sions and extend over the top -and slope of a ridge which rises to some 
elevation above the level of the stream and covering more than 200 acres 
of surface. The exposures are reported to be more or less continuous 
over an area of several miles extent in this part of Cabarrus County. 

Prior to the Civil War, when the early buildings of Davidson College 
were being constructed, the foundations, steps, and sills were quarried 
from one of the larger boulders exposed on the ridge slope in Cabarrus 
County. No recent openings have been made in the rock at any point. 
The outer portions of the boulders consist of hard and firm though par- 
tially decayed rock, the feldspars of which are more or less dull and with- 
out lustre from alteration and the biotite is somewhat altered, discoloring 
the rock with the liberated iron oxide. This form of decay extends in- 
ward from the surface of the rock for some distance. Although the 
buildings on the college campus at Davidson in which the granite was 
used were erected about 1860, the weathering effects appear to be no more 
7 



78 BUILDIXG AND ORNAMENTAL STONES OF NORTH CAROLINA. 

ap|3reciable than when the stone was first quarried. The rock used was 
from the surface and did not represent the entirely fresh granite. 

The granite exhibits good working qualities in the natural exposures 
and it is in all respects an excellent stone, well suited for most purposes 
for which granite is used. 

Microscopical Examination. — A thin section cut from as fresh a speci- 
men of the rock as it was possible to obtain showed microscopically a 
biotite granite of medium texture. The principal minerals were ortho- 
clase, microcline, much plagioclase, quartz, biotite, titanite, titaniferous 
magnetite, altered peripherally or rimmed by the usual colorless titanium 
mineral, epidote, and chlorite. Both the feldspars and biotite contain 
inclusions and some evidence of the effects of dynamic forces are indi- 
cated in the. section. No injurious or harmful minerals are present. 

THE KNOX QUAERY. 

One and three-quarter miles S. 70° W. of Davidson an exposure of 
granite was being worked during the summer of 1903 by blasting, and 
the quarried stone was being used for macadamizing the roads in the 
vicinity of Davidson. The rock is a medium-textured, moderately light 
to dark gray biotite-granite of entirely massive structure but intersected 
by close jointing and is lacking in uniform color and texture. 

Four sets of joints intersect the granite mass at close intervals, striking 
N.-S., E.-W., N". 20° E., and N. 45° W. Most of the joint-plane sur- 
faces are slickensicled as a result of subsequent movement in the granite- 
mass. The rock is soft from partial alteration for the entire depth of 
the opening, 12 feet. Several feet of the gray and red residual granite 
decay covers the hard granite which must be stripped before working. 
The rock is unsuited for any purpose except for the rougher grades of 
work. 

Microscopical Examination. — A thin section cut from a specimen of 
the rock collected 3 miles southwest of Davidson on the new macadam 
road showed microscopically a biotite granite composed of quartz, potash 
and plagioclase feldspars, and biotite. The biotite is largely altered to 
chlorite and epidote. Prismatic inclusions of apatite are rather abund- 
ant in the feldspars. No harmful minerals occur in' the section. 

THE BLAKELY QUARRY. 

One mile southwest of Davidson, two small openings have been made 
in exposures of a medium-textured, light gray, biotite-granite to obtain 
stone for macadamizing the roads in the vicinity. The openings are in 



THE VARIETIES OF BUILDING STONES. 79 

a northwest-southeast alignment, about a quarter of a mile apart, and 
will average about 25 yards square, worked to a depth not exceeding 8 or 
10 feet. 

The biotite occupies well denned areas in the rock in the form of 
minute groups or bunches of aggregated intergrown shreds, which im- 
part somewhat of a mottled appearance to the granite. The largest of 
the areas will not exceed an eighth of an inch in diameter. 

Decay of the Granite. — Over most of the Davidson area the granite is 
deepty weathered, yielding a characteristic light-gray sandy to red gritty 
clay. The roads which lead in all directions from Davidson crossing the 
granite, show typical sections of shallow depth of the granite decay. 
Especially favorable were the conditions along the road that was being 
graded and macadamized during the summer of 1903, southwest from 
the town. Sections of the granite decay, 10, 20, and 30 feet in 
depth were numerous along this road for a distance of several miles from 
Davidson, and in every case examined the decay represented an advanced 
stage of weathering. In much of it none of the original minerals are 
identified, megascopically, but they have been apparently completely 
altered into the usual by-products. In other parts of the decay the stage 
of weathering is less far advanced and the original minerals are easy of 
determination by the unaided eye. 

Dikes of Basic Intrusive Rocks. 

Intrusive dikes of basic composition, including principally diabase and 
diorite and their altered equivalents, have rather wide distribution over 
nearly all parts of Mecklenburg County, that were studied. It is re- 
gretted that the time available for the preparation of this report does 
not permit of a petrographic description of this class r»f igneous rocks, 
but the material will be studied and reported on later. For the present 
it is only possible to briefly mention these rocks under each county in 
which they have been noted. 

Between the main line of the Southern Railway and the Pineville road 
on the Smith place, 4 miles south of Charlotte are large piled masses 
of boulders and smaller fragments of basic eruptive rocks of many dif- 
ferent types. Corresponding types of these rocks were observed in place 
at a number of points along the road farther south, which can be utilized 
for various purposes, especially for road macadam. 

Dikes of diabase have been noted at the following points to the east 
and southeast of Charlotte, which cut the granite in many cases: At 
the intersection of Lawyers' road and Seventh street; in the city limits 



80 BUILDING AND ■ ORNAMENTAL STONES OE NORTH CAROLINA. 

near the intersection of Seventh street by Pine; near the crossing of the 
stream by road leading to Belmont Springs, one mile east of Charlotte; 
the City granite quarry, near the freight depot; and at the Orders quarry 
just beyond the southeast limits of the city. 

Dikes of basic igneous rocks have been noted at the following points 
along the Fayetteville and Concord roads between Charlotte and the 
county line, in a general northeast direction from Charlotte: Two and 
a half miles northeast of Charlotte on the Concord road; 3^ miles north- 
east of Charlotte on the same road; and 5 miles northeast of Charlotte; 

7 miles northeast of Charlotte on the Rocky Eiver road, on the Alexander 
and Orr places; 2 miles north of NewelPs Station on the same road; 2-J 
miles north of NewelPs Station on the same road; in cut of the Southern 
Railway 12 miles northeast of Charlotte ; 8J miles northeast of Charlotte 
on the Stegall place; on the Fayetteville road between Morning Glade 
Church 12 miles northeast of Charlotte to within 8J miles of the city. 

In the northern part of the County along the Concord road, leading 
east from Davidson, between Davidson and the county line, several 
dikes of diabase were observed penetrating the granite. Also southwest 
of Davidson, 1^ miles along the newly graded macadam road a large dike 
of diabase penetrates the granite. 

IREDELL COUNTY. 

The granite area described above in the northern part of Mecklenburg 
County under the Davidson area forms the southward extension of a 
very extensive area covering the southern part of Iredell County. The 
granite is exposed in numerous outcrops in and about Mooresville, 6 to 

8 miles north of Davidson, where a number of quarries have been 
worked. Unlike the southern portion of the area exposed around David- 
son in the northern part of Mecklenburg County, the Iredell area exhibits 
2 typical phases of the rock, namely, fine, v even-granular and porphy- 
ritic in texture. The relations between these two phases of the granite 
are fully discussed below. The presence of hornblende in a part of the 
granite to the east of Davidson has not been observed in any part of the 
Iredell area, but biotite forms at all times the characterizing accessory in 
every outcrop of the granite examined in this part of the County. 

Both the even-granular and the porphyritic granite are traced north- 
ward from Mooresville to Barium Springs, a station on the Charlotte- 
Statesville branch of the Southern Railway, 12 miles north of Moores- 
ville and 4 miles south of Statesville. Many of the outcrops of the 
granite around Barium Springs show a decided schistose structure, a fea- 



THE VARIETIES OE BUILDING STONES. 81 

ture entirely absent from the Mooresville area, but is similarly shown in 
some of the outcrops to the southwest of Davidson, in Mecklenburg 
County. 

Between Barium Springs and Statesville, the country-rock is typical 
mica-schist grading, in places, through increased quartz, into a quartz- 
micaceous-schist 'penetrated by large and small veins of white crystalline 
quartz. The schist is more or less feldspathic and is at all times deeply 
decayed, yielding a deep-red soil, and preserving in -a remarkable degree 
the scliistosity planes of the fresh rock, in many sections of the decay 
examined along the roads. No contacts between the granite and schist 
were observed, due likely to the lack of exposure of the fresh or moder- 
ately fresh rock, where contacts, should they be present, would be ex- 
pected. 

THE MOORESVILLE GRANITE AREA. 

The Even-Grained Granite. 

A number of quarries, opened in the even-granular granite have been 
worked principally for monumental stock, within several miles of the 
town of Mooresville. The monument in the Raleigh cemetery, marking 
the grave of former State Geologist, Professor W. C. Kerr, is from 
the Mooresville granite. Eight inch cubes, in the rough, hammer dressed 
and polished faces are among the building stone collections in the State 
Museum at Ealeigh. 

THE MCNEELY QUARRY. 

One mile N. 70° W. of Mooresville several small openings have been 
made along a line of flat boulder outcrops, traced perhaps over a half- 
dozen acres of surface. The openings are all small and have not been 
worked to a depth exceeding 6 or 8 feet. Only one set of visible joints 
penetrate the granite in these openings, striking N". 65° W. A few 
knife-edge seams of feldspar intersect the granite in places. Biotite 
manifests a tendency to segregate in minute blotches containing several 
shreds to the area, similar to that in the Oglesby blue granite in Elbert 
County, Georgia, which is regarded as a very superior monumental gran- 
ite. In general appearance the 2 granites bear a strikingly close re- 
semblance to each other. No minerals, such as free sulphides and oxides, 
likely to cause discoloration on exposure of the rock were visible megas- 
copically. 

The rock is a fine-grained, dark blue-gray, biotite-granite of good 
quality. Excepting the very small blotches of biotite, which do not ex- 



82 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

ceed several millimeters across nor in anywise detract from the good 
qualities of the stone, the biotite is evenly distributed through the granite 
and imparts a very uniform color throughout. The granite is also 
equally uniform in texture and it is entirely massive. 

• Microscopical Examination. — Microscopic study of a thin section of 
the rock from this quarry shows a fine-textured biotite granite, composed 
of orthoclase, microcline and microperthitic intergrowths, a sprinkling 
of stout laths of striated acid plagioclase, quartz, biotite, titanite, apatite, 
zircon, chlorite, and epidote. 

Feldspar, including microperthite and a little plagioclase, is the most 
abundant constituent. Biotite is distributed rather uniformly in large 
amount through the section in the form of shreds and elongated plates of 
the usual color- and absorption, and is partly altered to chlorite and a 
little epidote. Titanite of strong pleochroism and in complete idiomor- 
phic and granular form is present in large quantity. A rather unusually 
large distribution of quartz-feldspar intergrowths as micrographic struc- 
ture occurs, indicating simultaneous crystallization of the quartz with a 
part of the feldspar. 

The small amount of the stone quarried is reported to have been used 
exclusively for monumental stock. In addition to the uniform color 
and texture, the stone shows strong contrast between the cut and polished 
surfaces, an essential feature in a high grade monumental granite. 

This massive fine-grained, even-granular granite cuts the porphyritic 
granite, and good sharp contacts between the two texturally unlike gran- 
ites are found in a number of places near the openings In the decayed 
products of the 2 rocks. The nature of the contacts indicate that the 2 
granites are not phases of the same rock, but that they are separate intru- 
sions. Near the west opening a diabase dike less than 6 feet across pene- 
trates the porphyritic granite, striking in a general northwest direction. 

THE BKEED QUARRY. 

One and a half to 2 miles southwest of Mooresville, two openings, 
one-fourth mile apart in an east- west direction, have been worked in out- 
crops of granite similar to that of the McNeely quarry. The east 
opening, which is the largest one and was formerly known as the Breed 
quarry proper, has been worked at intervals on a small scale since first 
opened in 1886. The opening is made in a ledge outcrop along a small 
branch at the foot of a moderate hill-slope, the top of which rises prob- 
ably 20 to 25 feet higher in elevation. In places the working has ex- 
tended below the level of the stream. Along the surface the exposure 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE IX 




A. THE BREED QUARRY, I T/ 2 MILES SOUTHWEST OF MOORESVILLE, IREDELL COUNTY. 




B. BOULDER OUTCROP OF AUGITE-SYENITE, 4 MILES SOUTHWEST OF CONCORD, CABARRUS COUNTY. 



THE VARIETIES OF BUILDING STONES. 83 

is more or less bouldery in character and in order to obtain dimension 
stone of fresh quality, stripping to a depth of 8 or 10 feet is neces- 
sary. It has been opened for a distance of about 200 feet along the 
ledge direction, and the quarrying has extended into the hill-slope for a 
distance of about 50 feet exposing a quarry-face of about 35 feet in 
depth. The face is not an even, smooth one, but it is much broken and 
ragged in outline, clue probably more to the method of quarrying than 
to an}^ natural condition of the rock. 

About midway of the length of the opening the face exposes a zone 
not less than 30 feet wide of very close jointing, from which dimension 
«tone can not be quarried. At any other point along the opening, stone 
of any dimension can be readily obtained (see Fig. A, PI. IX). 

Three sets of joints intersect the rock in the opening, striking E.-W., 
N.-S., and NW.-SE'., the latter set being less prominent than the first 
two. In addition to the vertical joints, the stone is broken into nearly 
horizontal layers 3 to 8 feet thick. The vertical jointing is usually 
spaced at wide intervals, 18 to 20 feet and more, which admits of stone 
being blocked out of this length and of the thickness mentioned above. 

The rock is a fine-grained, dark blue-gray biotite-granite of uniform 
texture and color. Hand specimens of the rock can not be distinguished 
from that of the McNeely quarry. It is rather a hard granite but it is 
reported to work well and it takes an excellent polish. It is in every 
respect a very desirable granite for monumental purposes for which it 
has been used. 

Microscopical Examination, — Microscopically, the rock is a fine-tex- 
tured biotite-granite identical with that described above from the Mc- 
JSTeely quarry. Orthoclase and microeline are in nearly equal propor- 
tion, with only 1 or 2 grains of plagioclase noted in the section. Bio- 
tite of deep brown color and strong pleochroism is present in large 
quantity, largely altered to chlorite and a colorless mica. Micrographic 
intergrowths of quartz and feldspar are very much less abundant than 
in the granite from the McNeely quarry. A little epidote, pleochroic 
titanite, and large numbers of inclusions of apatite are noted. 

A spur track was laid from the main line near Mooresville to the 
quarry for handling the stone. The granite has been shipped to various 
points in the State for use as monuments. 

The west opening was made some years later than the east one, about 
1891, or '92, and was then known as the Johnson quarry, but it has been 
subsequently purchased by the Charlotte Granite Company. The con- 
ditions at this opening are favorable to quarrying on a large scale. The 



84 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

rock is identical with that from the east opening except that the biotite 
indicates the same tendency to segregation in minute areas similar to 
that in the McNeely quarry, imparting a slightly speckled appearance 
to the granite. 

The following is a chemical analysis of the granite from the west 
(Johnson) opening: 27 

Analysis of granite from neat Johnson Opening. 

I. II. 

SiO, 66.01 69.53 

A1 2 3 . 17.44 16.46 

Fe 2 3 5.62 1.15 

Mn0 2 0.23 

CaO 1.44 2.19 

MgO 1.11 0.85 

Na 2 5.06 5.00 

K 2 3.16 4.91 

Loss on ignition None 0.91 

Total 100.07 100.91 

I. Analysis of granite from the west opening, iy 2 to 2 miles southwest of 
Mooresville, Iredell County, North Carolina. 

II. Analysis of granite from the Diamond Blue Granite Company's Quarry, 
Oglethorpe County, Georgia. Thomas L. Watson, analyst. 

The resemblance of the Mooresville granite to the Oglesby dark blue- 
gray granite in Elbert and Oglethorpe counties, Georgia, has already 
been remarked on. In order to make clearer this relationship between 
the 2 rocks, an analysis of the Georgia rock is given in column II 28 
for comparison with that of the Carolina rock in column I. 

Beautiful contacts between the fresh, fine-grained granite and the 
fresh porphyritic granite occur at the east opening, the description and 
nature of which are given below under the porphyritic granite, where 
the relations between the two rocks are discussed. 



THE BIDDELL QUARRY. 

Three miles N. 30° E. from Mooresville and one-quarter of a mile 
north of the Mooresville-Salisbury road, several small openings were 
made in 1891 in exposures of a similar granite to that described above 
under the McNeely and Breed quarries. The rock is reported to have 

27 Lewis, J. V., Notes on Building and Ornamental Stone, First Biennial Report, N. C. 
Geol. Survey, 1891-92 (1893), p. 87. 

28 Watson, Thomas L., A Preliminary Report on the Granites and Gneisses of Georgia, 
Georgia Geol. Survey, Bull. No. 9A, 1902, p. 191. 



THE VAKIETIES OF BUILDING STONES. 85 

been worked for building stone which was shipped to the Pennsylvania 
markets. The openings are in a ledge outcrop exposed along a small 
branch at the foot of a long but gentle hill-slope. Large boulder out- 
crops of the granite are found some distance back from the stream on 
both sides, and they were traced along the branch for a considerable 
distance. The principal opening is in a ledge which rises 15 to 25 feet 
above the water-level in the branch and it is 150 feet long by 15 feet deep. 

Jointing is spaced at wide intervals of which there are 2 sets strik- 
ing N.-S., and N. 65° E. Small segregation veins and dikes of peg- 
matite, composed of white and pink feldspars, large plates of biotite, 
and some quartz, are numerous. These intersecting materials vary from 
one inch to more than 12 inches across and they cut the granite 
indiscriminately. Frequently they are found crossing each other, and 
hardly a block of any size of the stone that has been quarried is entirely 
exempt from them. For this reason the stone is restricted in its use, but 
in all other respects it should prove to be desirable for all purposes to 
which granite is usually put. It is quite possible that openings made 
in outcrops of the granite in other parts of the same area would yield 
dimension stone free from the intersecting materials. 

The rock in the opening is a medium blue-gray granite, and is the 
same rock as that in the McNeely and Breed quarries. It varies in 
texture from medium to fine-grained and the slight speckled appearance 
due to the biotite exhibiting a tendency to segregate in minute blotches 
or areas is apparent. An additional wavy appearance of light and 
darker-colored streaks due to increased or diminished biotite, blending 
into each other, appear, in places, through the stone. 

Microscopical Examination. — A thin section of the rock from this 
quarry shows, microscopically, a fine-textured biotite-granite composed 
of an aggregate of intricately interlocking quartz and feldspar, in which 
lie considerable shreds of biotite. Microcline is the predominant feld- 
spar with some orthoclase and a little striated plagioclase, all of which 
contain more or less inclusions of prismatic apatite. Biotite has its 
usual distribution, color, and absorption, and it is altered to both chlorite 
and epidote. Micrographic intergrowths of the quartz and feldspar are 
developed through the section. A few small grains of magnetite occur. 
The rock is in all respects the same as that described from the McNeely 
and Breed quarries above. 

The porphyritic granite extends several miles further in a northward 
direction along the Mooresville-Salisbury road, and it is of the same 
character as that exposed around Mooresville and Mount Mourne. 



86 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

THE COTTON MILL OUTCROP. 

Near the cotton mill in the southern limits of Mooresville, the fine- 
grained granite is exposed in several large boulders along the railroad 
and the main street. The rock is uniform in color and texture and is 
identical with that described in the Breed and McNeely quarries. 

The Porpliyritic Granite. 

The porpliyritic granite constitutes the main body of the rock in the 
Mooresville area. It is traced east of north from Mooresville along the 
Salisbury road for a distance of about 5 miles. To the south, south- 
west and west of Mooresville, it has been traced for a distance of ap- 
proximately 3 miles in each direction. The rock is exposed in a 
number of large flat-surface outcrops in the vicinity of Mount Mourne, 
a station on the Southern Railway, %\ miles south of Mooresville. Over 
the entire area the porpliyritic granite maintains remarkable uniformity 
in both color and texture. 

Where exposed, the groundmass of the granite is medium coarse 
grained and dark gray in color from the presence of much biotite. It 
is composed of the essential minerals quartz, feldspar, and biotite. 

The phenocrysts are composed of potash feldspar, usually twinned 
after the Carlsbad law. They are largely flat-tabular, idiomorphic in 
outline, ranging from J to 2 inches in length hj J to f of an inch across 
and are either white or pink in color. As a rule, the phenocrysts do not 
grade into the same constituent of the groundmass, but they are in most 
cases conspicuously developed and are sharply defined from the ground- 
mass feldspar. Usually no marked orientation is observed in the pheno- 
crysts, but at several exposures a slight tendency toward such was some- 
what apparent. In every exposure of the porpliyritic granite examined 
the phenocrysts showed more or less included biotite of the groundmass, 
and frequently as large in size. The ratio of the phenocrysts to the 
groundmass is approximately one to one, with but little variation from 
this in any of the outcrops examined. 

In the fresh rock the phenocrysts are often of a pronounced pinkish 
color, but in the weathered granite they are entirely white and opaque 
from partial kaolinization. Over much of the area the granite is more 
or less deeply decayed and in sections of the decay the phenocrysts oc- 
cupy their original positions in it as in the fresh rock. In such they are 
usually white and unstained, and with the loose scattered ones over the 
surface they afford an easy means of readily tracing the underlying fresh 
granite. Some sections in the decayed rock indicate weathering of the 



THE VARIETIES OF BUILDING STONES. 87 

rock into thin layers affording the appearance of a pronounced gneissic 
structure. 

The best exposures of the fresh porphyritic granite are found about 
one-half mile north of Mount Mourne and at the Breed quarry 1^ to 2 
miles southwest of Mooresville. Outcrops of the partially or completely 
decayed rock are rather numerous over the entire area. 

THE MOUNT MOURN E EXPOSURE 

One-half mile north of the station and 200 to 300 yards west of the 
railroad, a flat-surface exposure of the porphyritic granite known as "Flat- 
rock '■ occurs of about one acre in extent, from which some of the surface 
stone was quarried prior to the Civil War for foundations in some of the 
buildings of Davidson College. The rock as a whole exhibits the same 
characteristics as in the general description given above of the entire 
area. Both phenocryst and groundmass conform to this description. 

At this point the porphyritic granite is cut by a dike of fine-textured 
dark blue-gray biotite granite similar to that in the McNeely and Breed 
quarries. The dike is quite irregular in outline, varying from 6 to 
12 inches across, with a general northeast strike, and it is regarded 
as an apophysis from the main body of the same dark blue-gray granite. 
Small stringers or fingers given off from the dike penetrate the por- 
phyritic granite, and at several places near the contact, the porphyritic 
granite is included in the dike as small irregular areas. 

Microscopical Examination. — A thin section of the rock from this 
opening examined under the microscope shows a medium-textured por- 
phyritic biotite-granite composed of microcline, a little orthoclase, and 
some striated plagioclase, quartz and biotite. Microcline is porphyritically 
developed and exhibits the micropoikilitic structure. Micrographic inter- 
growths of the quartz and feldspar are freely distributed through the 
section. Biotite has its usual distribution, color, and absorption, and it 
is closely associated with deep brown strongly pleochroic titanite and 
some epidote. Both the biotite and titanite contain inclusions, among 
which are apatite and magnetite. Apatite inclusions are also character- 
istic to some extent of the feldspar constituent. 

Nature of the Contact at the Breed Quarry. — The contact here is be- 
tween the fresh rock of the 2 granites and it affords an excellent op- 
portunity for study of the relations between them. Here as at other 
points over the area the contact between the two rocks is entirely sharp 
and well defined. The texture of the porphyritic rock is well emphasized 
and of typical development. The phenocrysts are pink in color con- 



88 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

forming in all other particulars to the general description above. The 
groundmass is dark-gray in color and medium coarse-grained in texture. 
It is uniformly coarser grained than the even-granular granite with which 
it forms the contact. 

Frequent inclusions of the porphyritic granite of irregular outline and 
in size ranging from very small areas one and more inches in diameter 
to those several feet across are found in the even-granular granite, here 
and along the contact. These areas are sharply defined from the host. 
jSTear many of the included porphyritic granite areas in the even-granular 
granite numerous segregated areas of the biotite are formed in the latter 
rock. These are usually of irregular outline and small in size, measuring 
3 to 4 inches long by 1 to 2 inches across and fail entirely at some dis- 
tance away from the contact. More or less pronounced banding, differ- 
entiation of the light and dark minerals into parallel layers, is only 
observed along the contact between the two rocks. 

Microscopical Examination of the Porphyritic Granite. — Under the 
microscope a thin section of the rock from near the Breed quarry shows 
a porphyritic biotite granite of medium texture. The groundmass con- 
sists of orthoclase and microperthitic intergrowths, a little striated feld- 
spar, quartz, biotite, and much titanite. Intergrowths of quartz and 
feldspar in micrographic structure together with the usual inclusions of 
apatite and zircon, occur. Biotite is more or less altered to chlorite and 
a little epidote. The biotite is closely associated with titanite which oc- 
curs in the form of crystals and grains of marked pleochroism and 
cleavage, and filled with minute grains of black oxide of iron. 

Microcline and microperthite compose the phenocrysts which strongly 
exhibit micro poikilitic structure, the inclusions of which are both potash 
and plagioclase feldspars, quartz, and biotite. Microcline fails entirely 
in the groundmass. It will be observed from the microscopic descrip- 
tions of the porphyritic and the even-granular granites at the Breed 
quarry that they only differ texturally, with essentially the same mineral 
composition. 

RELATIONS OF THE GRANITES IN THE MOORESVILLE AREA. 

From the general description of the even-granular and the porphyritic 
granites described above, and the nature of the contact where observed 
between the 2 rocks, it is reasonably conclusive that the 2 granites 
do not represent different facies of the same rock. Were this true the 
line between the 2 rocks should mark a zone of more or less transition 
from the porphyritic to the even-granular rock and not as in every case 



THE VARIETIES OF BUILDING STONES. 89 

observed indicate a sharp contact. Furthermore, certain phenomena de- 
veloped along this line would be difficult of explanation on this supposi- 
tion. On the other hand the evidence strongly supports the argument 
that the porphyritic rock is the oldest and that the even-granular granite 
is intrusive in it. The sharpness of contact ; the prevailing coarser texture 
of the porphyritic granite than that of the even-granular granite along 
the contact; the banding in places along the contact, and inclusions of 
the porphyritic granite in the even-granular granite ; and the occurrence 
of probable apophyses of the fine-grained rock penetrating the porphy- 
ritic granite, certainly support this belief. 

It is true that the two granites only differ from each other in texture, 
both having the same mineral composition and in general necessarily 
closely similar chemical composition, a feature often observed in separate 
facies of the same granite mass. 

THE BARIUM SPRINGS GRANITE AREA. 

To the west of the depot and at the Springs proper, three small open- 
ings, near together, have been made in a porphyritic granite. These were 
made many years ago to obtain stone for bridge construction over the 
County. 

The rock is quite variable in texture and in color, ranging from a fine- 
textured dark gray biotite to a medium-fine to coarse-grained porphyritic 
granite of light gray color. The porphyritic phase of the rock is more 
or less schistose in places. The phenocrysts are usually irregular in out- 
line, occasionally idiomorphic, and of variable size, measuring in extreme 
cases 2 inches long by J of an inch wide. They contain biotite inclusions 
and are frequently twinned on the Carlsbad law. 

Two sets of joints intersect the granite mass, which strike N. 70° E., 
and N\-S. The strike of the schistosity when observed approximated 
N. 45° E. The jointed surfaces are slickensided, thinly coated by a 
yellowish green mineral substance. The spring waters issue from and 
along the jointed surfaces in the granite, and they are reputed to have 
considerable medicinal value. 

Microscopical Examination. — Under the microscope a thin section of 
the rock showed a fine-textured biotite granite-gneiss in which the gneissic 
structure is pronounced, and extensive shattering or crushing and re- 
crystallization of the mineral grains indicated. The essential composition 
of the rock is potash and plagioclase feldspars largely, orthoclase with 
scant microcline, quartz, and biotite. The biotite shreds are arranged 



90 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

along parallel lines, and they are intergrown with some shreds of mus- 
covite. Occasional areas of micrographic intergrowths of quartz and 
feldspar are noted. 

THE MURDOCH PLACE. 

About 4 miles slightly east of south from Statesville and 1| 
miles east of Barium Springs, a fine-textured, massive, medium- 
gray muscovite-bearing biotite-granite has been slightly opened. The 
rock is exposed in the valley of a small stream and was worked some 10 
to 12 years ago to obtain stone for local use. The opening is a very 
small one and only a few stone were quarried. So far as could be judged 
from the opening, the rock contains no injurious minerals; is entirely 
free from veins and other intersecting materials ; and is a rather desirable 
granite. 

Microscopical Examination. — Microscopical^, a thin section of the 
rock revealed a fine textured biotite granite, composed of potash and 
plagioclase feldspars, quartz, and biotite. The feldspars and biotite are 
both largely altered yielding much colorless mica, epidote, and chlorite. 
Microcline is very subordinate in amount, but plagioclase is present in 
considerable quantity. Simultaneous crystallization of a part of the 
feldspar with the quartz is indicated in the micrographic structures as 
small areas distributed through the section. The effects of pressure- 
metamorphism are very pronounced in the minerals of the section. 

THE WILHELM PLACE. 

About 5-J miles southwest of Statesville (7 miles by the road) and 
about 2 miles from Catawba Eiver on Doctor Wilhelm's place, an outcrop 
of granitic gneiss was worked for bridge piers some years ago. The open- 
ing is a small one and is made in an exposure of the gneiss just above a 
large spring, \ mile off the Shoal's road. 

The rock is a dark gray biotite granite gneiss, thinly schistose, and 
of medium texture. It is rather uniformly banded and, apparently would 
prove to be a desirable stone for street purposes. 

Between the Wilhelm opening and Statesville the country-rock is mica- 
schist intersected in places by veins of crystalline quartz varying from 
several feet to 100 feet in width. Similar conditions obtain between 
Statesville and Barium Springs. 

THE MILLS PLACE. 

One and a half miles north of Statesville, on W. B. Mills' place, a small 
quantity of stone has been obtained for macadam purposes from an ex- 



THE VARIETIES OF BUILDING STONES. 91 

posure of gneiss. The rock is exposed along a small stream at the foot 
of a moderate hill slope. It is a very dark, coarse-textured porphyritic 
biotite gneiss, containing a large proportion of biotite. The feldspar 
phenoerysts are not abundant, but are large in size and of irregular out- 
line, transparent and with good cleavage development. The fresh rock 
is covered quite deeply by deep red to chocolate colored residual clay. 
The. stone is only suited for the rougher grades of work. 

All along the public highway in this locality the rock decay is quite 
deep, varying from a dark red to chocolate brown, intermingled with 
considerable limonitic clays exposed in places, and the whole derived 
largely from a thinly schistose hornblendic rock. 

Basic Igneous Intrusive Bocks. 

The only dike of diabase observed in Iredell County is that mentioned 
under the McNeely quarry, one mile N. 70° W. of Mooresville. It is less 
than 6 feet across, striking N. 45° W., and penetrates the porphyritic 
granite. 

In a general easterly direction from Statesville along the Statesville- 
Elmwood road, the rock between Statesville and Elmwood is identified 
as mica-schist from the residual decay. No fresh rock is exposed. About 
a quarter of a mile west of Elmwood along the same road, the schist is 
cut by a dioritic mass. The decay of the 2 rocks, schist and diorite, 
is strongly contrasted. The cliorite is exposed over a large area in the 
form of large and small boulders, as far as sectioned, a distance of 5 
or more miles 1ST. N". E., from Elmwood. The rock is also reported as 
, outcropping several miles to the southwest of Elmwood, and again to 
the northeast along the Cool Springs road where specimens were collected. 

The diorite is penetrated in a number of places by very light colored, 
fine-textured granite dikes, which range from 3 to 12 inches in width and 
strike ir a general northwest direction. This area is asbout 5 miles west 
of Barber Junction, where large exposures of typical diorite occur, and 
the Elrnwood rock probably represents the westward extension of the 
Barber area in Eowan County. Between the two places, Elmwood and 
Barber, some mica-schist covers the diorite from view. 

CABARRUS COUNTY. 

Large areas of granite are found over many parts of Cabarrus County, 
limited principally to the west half of the County. The granites proper 
are biotite-bearing and include both porphyritic and even-granular rocks. 
Massive and schistose phases occur and in texture they vary from medium 



92 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA ■ 

to fine-grained. Exposures are numerous mostly in the nature of large 
and small boulders, with frequent ledge and flat-surface outcrops. 

Schists of chloritic, sericitic and argillaceous types, intersected by large 
quartz veins and dikes of basic igneous rocks, compose the rocks of the 
eastern part of the County. The strike of the schistosity is N". 20°-30° 
E., with dips N". 70°-80° W. Eruptive basic rocks in the form of dikes 
are common to both the granite and the schist areas of the County. 

As yet very little quarrying has been clone; 3 small openings will 
include the extent of quarrying in the county. The lack of developments 
in some of the larger and more important areas prevents positive state- 
ments of the commercial value of the granite. 

ROCKY RIVER GRANITE AREA. 

Entering the County from the southwest, at a point close to but south 
of the Southern Eailway, northeast of Charlotte, a section made in a 
general northeast direction to Concord, the county-seat, traverses granite 
for nearly the entire distance. 

THE TEEDEES PLACE. 

Along the east side of the Southern Eailway and less than a quarter 
of a mile west of the Eocky Eiver road and approximately one mile south- 
west of Fore's mill on the river is an extensive area of granite. The 
rock is continuously exposed in large and small bouldery masses over not 
less than fifty acres of surface, in a general direction parallel to the rail- 
road. Scattered small outcrops of the same rock are traced northward to 
the river at the mill, where the exposures again assume large dimensions 
and the rock is of decidedly coarser texture. The rock has not been 
opened but the exposures on the Teeders place show a firm and even- 
textured biotite granite of moderate dark gray color, and, in places, 
slightly schistose in structure. Measurements of the jointing in the ex- 
posures at the mill showed two sets of planes, striking N. 40° W., and 
N". 70° JE. The area is readily accessible, and so far as could be judged 
from the surface exposures, the rock is of good quality. The coarse- 
textured rock crosses the river at the mill and is recognized by its decay 
for some distance along the road. 

THE STEWART PLACE. 

About 4 miles west of south from Concord on the Stewart Place 
and near the railroad crossing over Coddle Creek, a fine-textured dark 
gray biotite granite ( ?) outcrops in boulder form on both sides of the 



THE VAEIETIES OF BUILDING STONES. 93 

Eocky Eiver road. The rock somewhat resembles that described above 
on the Teeders place. No openings have been made. Hand specimens 
were collected from a small exposure on the road side within a few paces 
of the Stewart house. 

Diorite is exposed along the road between Eocky Eiver and Coddle 
Creek, 5 to 6 miles west of south from Concord. On the north side 
of and less than a quarter of a mile from Eocky Eiver along the same 
road, a diabase dike penetrates the coarse-textured granite. 

SOUTHWEST LIMITS OF CONCORD. 

Near the southwest limits of the town of Concord and about 1^ 
miles from the center of the town immediately on the west side of 
the Eocky Eiver road, is a granite exposure, about 10 feet high and 
covering less than a quarter of an acre of surface. The rock is a uni- 
formly fine-textured pink granite of desirable quality. Jointing is in 
2 directions, spaced at close intervals, and limiting in size the blocks 
that would be possible to quarry. The strike of the joint-planes is 1ST.-S., 
and E.-W. No other exposures of the granite were found, hence the ex- 
tent of the rock could not be determined. Should the rock be found in 
quantity, and dimension stone be obtainable, the uniform color and 
texture make it a very desirable granite for use as monumental and 
decorative stone. 

Microscopical Examination. — Under the microscope a thin section of 
this rock shows a very fine-textured biotite granite made up of a complex 
interlocking aggregate of potash feldspars and microperthitic inter- 
growths, and quartz. Plagioclase as single individuals entirely fails. 
Very little biotite is distributed through the section and it is in small 
irregular flecks largely altered to the usual by-products. No injurious 
minerals occur in the rock. 

Augite Syenite. 

Beginning about 4 miles southwest of Concord, the Eocky Eiver 
road traverses an extensive area of coarse-textured augite syenite which 
extends within 1^ miles of the town of Concord. The area is approxi- 
mately 3 miles wide, measured in a southwest direction. Outcrops of 
the rock are numerous on both sides of the road, in the nature of im- 
mense boulders which measure 10, 20 and 30 feet high and proportion- 
ately large otherwise (see Fig. B, PL IX). Similar exposures are re- 
ported to the south and east of Concord, which would apparently mark a 
northwest-southeast belt of this area. See p. 265 for tests as road metal. 



94 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

The rock is of uniformly coarse texture over the entire area, of massive 
structure and composed of large bluish gray feldspar individuals, with- 
out pronounced crystal outline (allotriomorphic). It contains little of 
the other minerals, as a rule, but is largely made up of the coarse crys- 
tallization of feldspar. The large feldspar individuals are wrapped about 
each other and are closely interlocked, imparting a close texture to the 
rock as a whole. When closely examined, the feldspar shows a decided 
pinkish tone, but not of sufficient depth to be noticeable in the general 
color of the rock, which is a pronounced bluish gray. 

The small amount of ground mass present in the rock is coarse-textured 
and dark gray from the proportion of the dark bisilicates present. It 
occupies small but distinct areas between the larger feldspar individuals. 

Boulders of the partially decayed syenite are buried to some depth in 
a coarse-grained soil derived from the decay of the rock, which varies 
in color from yellowish red to very light rusty gray in color. Oxidation 
is only partially complete and the rock crumbles principally from the 
action of physical forces. 

At several points along the Rocky River road boulders of the syenite 
have been split and a few stone quarried for local use. About 3 years 
ago the Balfour Quarry Company opened a quarry in a large bouldery 
ledge outcrop of the syenite immediately on the Eocky River road, 3 
miles southwest of Concord on Mrs. Parrish's place. The rock was 
quarried for ballast. The opening is about 50 by 75 yards, and along 
the quarry-face it will average about 25 feet in depth. The stone is 
quarried by blasting and, in consequence, the rock is greatly shattered 
and torn (see Fig. A, PL X). Two sets of joints showing slickensided 
surfaces, cut the granite mass striking N". 40° W., and N". 40° E. 

Microscopical Examination. — A thin section of the rock from the 
Balfour Quarry Company's opening, 3 miles southwest of Concord, 
showed microscopically, a coarse-textured, augite-hornblende-biotite 
syenite composed very largely of feldspar with slight quartz, and the 
accessories mentioned. The feldspars are orthoclase, microcline, micro- 
perthitic intergrowths, and subordinate plagioclase (oligoclase). These 
are usually rimmed by a wide zone, or border, of a very fine-grained mosaic 
of the feldspar as a result of extensive pressure-metamorphism. The 
feldspars are further filled with minute closely crowded hair-like inclu- 
sions of rutile and small particles and granules of magnetite and minor 
accessories. Green augite (diopside) is the principal ferromagnesian 
silicate. Hornblende of green color exceeds biotite in amount. Both 
the hornblende and the biotite show some alterations. Considerable 
magnetite, some kaolin and a few grains of pyrite, with minor micro- 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE X 




A. BALFOUR QUARRY COMPANY'S QUARRY IN AUGITE-SYENITE, 3^2 MILES SOUTHWEST OF CONCORD, 

CABARRUS COUNTY. 




B. GRANITE BOULDER OUTCROP, DUNNS MOUNTAIN, 4 MILES EAST OF SALISBURY, ROWAN COUNTY. 



THE VARIETIES OF BUILDING STONES. 95 

scopic accessories occur. Quantitative expression for the principal 
minerals is: Orthoclase > < microcline > oligoelase > green augite 
(diopside) > green hornblende > biotite > magnetite > pyrite > 
kaolin. 

Porphyritic Granite. 

Landers is the name of a flag station on the main line of the Southern 
E ail way in the extreme southern portion of Rowan Count}'', near the 
Rowan-Cabarrus county line, and is adopted for the name of a large area 
of porphyritic granite exposed over the middle northern part of Cabarrus 
County, extending southward from near the station to within 4 or 5 
miles ncrth of Concord. 

On Schnlenberger's Branch where crossed by the Concord road, about 
three-quarters of a mile south of Landers, are flat-surface exposures 
of a medium coarse-textured biotite porphyritic granite of gray color. 
Exposures of the same rock occur along the Concord road, a few hundred 
paces east of the Southern Railway, between the railroad and the branch. 
The rock is continuously traced by occasional small outcrops of the 
moderately fresh granite and by its residual decay, along the same road, 
to within 4 or 5 miles northeast of Concord. The rock is strongly con- 
trasted with the augite syenite described above as occurring southwest of 
Concord. The proportion of groundmass to phenocryst is considerably 
increased and the porphyritic feldspars are white or very light in color. 

The phenocrysts exhibit both icliomorphic and allotriomorphic out- 
lines and at no point was orientation among them in the groundmass 
apparent. They are composed of potash feldspar and those of irregular 
outline pass by decreased size into the similar constituent of the ground- 
mass. Biotite inclusions are common in the porphyritic feldspar and 
twinning on the Carlsbad law is frequent. 

Microscopical Examination. — A thin section cut from a specimen of the 
porphyritic granite occurring 5-| miles nearly north of Concord 
indicated, microscopically, a biotite granite composed principally of 
orthoclase, microcline and microperthitic intergrowths, much plagioclase, 
quartz and biotite. The biotite is much altered to chlorite and is fre- 
quently crowded Avith inclusions. The feldspar contains a considerable 
proportion of included small particles of black iron oxide. Occasional 
crystals of titanite are noted in the thin sections. 

TSTo opening has been made in any of the exposures of the porphyritic 
granite over the area. Jointing is spaced at wide intervals, making it 
possible to quarry dimension stone of any desirable size. Scattered dark- 



96 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

colored areas of biotite segregations and occasional thin veins of feld- 
spar are observed in the rock in places. Pyrite is sparingly developed in 
small scattered grains and crystals, but it has not been noted in sufficient 
amount in any exposures of the rock to seriously injure the stone. 

As a rule, the rock yields a light gray siliceous decay, though deep red 
colors are often shown from increased oxidation of the iron-bearing con- 
stituent, indicating a more advanced stage in the chemical decay of the 
rock. In the usual lighter colored decay the feldspars are much kaolin- 
ized, chalky-white in appearance, and the rock crumbles to a coarse 
granitic sand, in which the original minerals of the fresh rock are fairly 
well preserved and can be readily identified. 

GRANITE ON THE EAST SIDE OF CONCORD. 

Along the Stokes ferry roacl, 7 miles east of Concord, near Adams 
Creek, a fine-textured, massive, light gray, biotite granite is exposed 
directly on the road side. The rock contains much pyrite disseminated 
through it as small crystals and grains. It is quite uniform in color and 
texture and it would prove to be a very desirable granite except for the 
amount of pyrite contained in it. 

Microscopical Examination. — Under the microscope a thin section of 
the rock from this locality, shows a biotite granite composed of the potash 
feldspars and striated plagioclase, the latter probably in excess, quartz 
and biotite. The biotite displays the usual alteration. Many large pieces 
of pyrite and some grains of magnetite are distributed through the sec- 
tion. Extensive shattering from dynamic forces is indicated in the very 
fine-grained mosaics of the quartz and feldspar. 

THE KEID OR CITY QUARRY. 

Near the northeast limits of the town of Concord, some stone has been 
quarried from an exposure of granite and used for macadam on the 
streets of Concord. The rock is exposed along a small stream, the open- 
ing in which is small, averaging about 35 by 50 yards with a quarry-face 
of 10 to 20 feet in depth. Jointing is at close intervals and makes it im- 
possible to quarry dimension stone. The strike of the joint-planes is 
N" : . 60° W. Abundant segregation areas of the ferro-magnesian minerals 
are distributed through portions of the rock, ranging from one to several 
inches in diameter, and usually more or less rounded in outline. On 
account of the close jointing and the numerous areas of dark-colored 
segregations, the stone cannot be used in first grade work. Results of 
tests of this rock for road material are given on page 265. 



THE VARIETIES OF BUILDING STONES. 97 

The rock is a medium-textured, biotite-hornblende granite of gray 
color. It is penetrated by a single dike of a basic igneous rock, striking 
N". 30° E. The rock composing the dike is thinly schistose in structure, 
but the enclosing granite is entirely massive, though indicating con- 
siderable movement in the mass in the complete development of slicken- 
sided joint surfaces. Clearly the granite was subjected to precisely the 
same metamorphosing influences as the dike, and that it is massive and 
not schistose indicates conclusively its greater resistance to pressure- 
metamorphism than that of the dike. 

Microscopical Examination. — Microscopically, the rock is a medium 
fine-textured, hornblende-biotite granite, composed of orthoclase, micro- 
cJine and a large proportion of a striated plagioclase, quartz, with nearly 
an equal quantity of hornblende and biotite. Both the hornblende and 
the biotite 'are considerably altered into a number of the most usual 
alteration products derived from these minerals. Crystals and grains of 
magnetite are quite freely distributed through the section. 

Granite Porphyry. 

Six miles east of Concord a deep pink, very fine-grained granite is 
exposed immediately in the Mt. Pleasant road. The exposure in the 
road is less than 100 feet across. Careful search failed to indicate further 
trace of the rock on either side of the road in the fields, and the cha- 
racter of the decay or soil away from the road on the two sides affords 
no indication whatever of the rock. In view of these facts no estimate 
as to the probable extent of the rock was possible. It is possible that 
the rock forms a dike whose width approximates 100 feet with a general 
approximate strike north and south. This, however, is entirely con- 
jectural and must be so accepted until other possible outcrops of the 
rock are found that will indicate the exact conditions. An 8 inch 
cube- of the rock collected from this exposure is exhibited in the building 
stones collection in the State Museum at Raleigh. It is susceptible of a 
high polish and its properties in general prove it to be a very desirable 
stone should it be found in quantity. 

Megascopically, the rock is a very fine-grained, deep pink or red feld- 
spar-quartz aggregate, in which no ferro-magnesion mineral is apparent 
to the naked eye. The texture is even graular with no semblance of 
the porphyritic texture indicated. 

Microscopical Examination. — Under the microscope a thin section of 
the rock from this locality indicates an intermediate texture between that 
of a normal granite and the matrix or groundmass of granite porphyry. 



98 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

The composition of the fine-grained aggregate is microcline, orthoclase, 
a little plagioclase, much quartz with no ferro-magnesian mineral in- 
dicated, but a few shreds of muscovite occasionally occur. The texture 
is exceedingly fine-granular with, under the microscope, a decided tend- 
ency to the porphyritic texture developed, in which quartz is the principal 
mineral showing this tendency. The quartz grains in many cases are 
conspicuously larger in development than those of the feldspar. They 
are entirely irregular in outline with no tendency toward idiomorphism 
indicated. The decided pink or red color of the rock is due to the dis- 
tribution of bright cherry red particles of iron oxide as inclusions in the 
feldspars, and further distributed along the sutures of the interlocking 
minerals and the microscopic fractures in the individual mineral grains, 
when such occur. 

SECTION ALONG THE ROAD FROM NEAR MT. PLEASANT TO CONCORD. 

Outcrops of the fresh rock were not exposed at any point along the Mt. 
Pleasant road, but excellent sections of the rock decay are numerous. So 
far as it was possible to identify the decay, the original rocks yielding it 
were of two principal t}^pes, diorite and granite. A careful study was 
made of the best exposures of the decay all along the road with the hope 
of making out the possible relations between the two rocks. 

The rock of dioritic composition is schistose in structure, much crushed 
and jointed. It is intersected by numerous quartz veins of variable 
width, from 1 to 12 and more inches across and by dikes of granitic 
composition of variable size. The decay is free from any decided red or 
yellow color which usually results from the oxidation of the iron-bear- 
ing mineral or minerals. 

In places the granite is fresh enough to indicate an original pinkish 
tint. The more decayed portions of the rock show a rusty-yellow to 
brown color, in which the original minerals of the unaltered rock are in 
a partially fresh state of preservation. Schistose structure was nowhere 
evident, but the decay indicated a completely massive granite of medium- 
coarse texture, penetrated by very many dikes of a dark greenish-colored 
basic material, more or less completely decayed. These dikes vary from 
one to several feet in width and the contacts made by them with the 
enclosing granite are entirely sharp and well defined. 

So far as it was possible to determine from the character of the decay 
derived from the 2 rocks, they do not appear to grade into each other, 
and they cannot be regarded therefore as facies of a single type. On 
the other hand, the facts as observed suggest that they represent separate 



THE VARIETIES OF BUILDING STONES. 99 

periods of intrusion. If they were both equally resistant to the dynamic 
forces, the diorite, since it is schistose and otherwise displays effects of 
pressure-metamorphism, must be regarded as relatively older than the 
massive granite. The somewhat close similarity of the granite dikes in 
composition to that of the main mass, found penetrating the diorite, ap- 
parently strengthens the belief that the diorite is older than the granite. 

A second section along the China Grove- Concord road in a general 
northerly direction from Concord denotes closely similar conditions to 
that just described along the road extending east from Concord to near 
Mt. Pleasant, About 4 miles and beyond east of north from Concord 
the decay has the appearance of that derived from mica-schist. From 
this point to within 1-J miles north of Concord the road traverses a belt 
of diorite, which is penetrated by numerous pink granite dikes. About 
1-| miles, north slightly east from Concord the diorite is in contact with a 
medium coarse-textured granite. Here as in the other section the contact 
between the 2 rocks is sharp and indicates no transitional zone or pas- 
sage of one rock into the other. 

Within the town of Concord sections showing the diorite-granite com- 
plex are exposed along several of the streets. Similar conditions obtain 
at a number of places in the cuts along the Southern Eailway to the 
north of Concord, and extending through several counties. 

Basic Igneous Rocks. 

Besides the areas of diorite described above to the east, north and 
southwest of Concord, dikes of basic rocks are frequent over the County, 
penetrating alike both granites and schist. Variation is from typical 
massive diabase to more or less schistose and altered hornblende types. 
These are in all respects the analogue of the basic dikes described in 
Mecklenburg and the adjoining counties. The more important ones are 
here noted. 

Xeai Eocky Eiver on the north side, a diabase dike cuts the coarse- 
textured granite exposed along the Concord road. Along .the same road, 
boulder outcrops of dioritic rocks are noted at several points between the 
above dike of diabase and Concord. 

On the Mt. Pleasant road, 5J miles east of Concord, a diabase dike 100 

feet wide and trending approximately northwest, intersects the schistose 

' diorite near the granite contact. Near the eastern limits of Concord, and 

beyond en the same road, numerous dikes of basic composition are found 

penetrating the diorite-granite complex. 



100 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Nitze 29 refers to diabase dikes penetrating the schists of the Gold Hill 
belt, which extends into the northeast part of Cabarrus County (p. 86) , 29 
and again 7 miles south of Concord (p. 121 ). 29 Also 12^ miles south of 
Concord on Caldwell creek, diabase and gabbro. are mentioned in their 
relations to the granite (p. 125 ). 29 

ROWAN COUNTY. 

One of the principal and most important granite areas in the State 
occurs near Salisbury in Rowan County. The area marks a nearly con- 
tinuous ridge beginning about 4 miles east of Salisbury and extending 
southwestward for a distance of more than 12 miles. Xumerous 
quarries have been worked over nearly all parts of the ridge and the stone 
has been widely used in North Carolina and the adjoining States for 
various purposes, principally as a general building and street rock. The 
first quarries were opened many years prior to the Civil War and quarry- 
ing has been continued at intervals to the present time. Both a light 
gray, nearly white, and a pink granite of uniform color and texture of 
most desirable quality are quarried on the ridge. 

A second area of even-granular biotite granite is developed in the 
vicinity of Woodleaf, a station on the Charlotte-Winston branch of the 
Southern Railway, about 11 miles northwest of Salisbury. A number 
of very small openings are made in places over the area and a small 
quantity of the granite has been quarried for local use. Between Salis- 
bury and Woodleaf, beginning 2 miles northwest of and continuing 
for a distance of 8 miles from Salisbury, on the Wilkesboro road, is 
a very large and continuous area of medium textured biotite, porphyritic 
granite. Exposures of the fresh rock are very rare, but the area is readily 
traced by the residual decay of the granite. 

In addition to the granites, basic igneous rocks are quite widely dis- 
tributed over the County, comprising the principal types, diorite, diabase, 
and gabbro. The latter rock, gabbro, is quarried at one point in the 
County for monumental stock, for which purpose it seems admirably 
suited. The other types of basic rocks might be used to advantage in 
certain grades of commercial work. 

The various areas of granitic and basic rocks are readily accessible to 
the lines of railway which traverse the County, rendering transportation 
facilities very favorable to the quarry industry in the different granite 
areas. The individual areas are described below. 

■*> Bulletin No. 3, N. C. Geol. Survey, 1896, pp. 86, 121, 125. 



THE VARIETIES OF BUILDING STONES. 101 

THE DUNNS MOUNTAIN GRANITE AREA. 

Dunns Mountain, located 4 miles east of Salisbury, the county-seat 
of Rowan County, forms a part of a conspicuous granite ridge some 
12 to 14 miles in length, trending in a general northeast-southwest direc- 
tion. The ridge character is more or less apparent throughout its course, 
but it becomes less well defined toward the southwest and in many 
places it can only be recognized from the rock exposures, which are 
not arched appreciably above the general level of the surrounding plain, 
but are more or less co-extensive with it. Dunns Mountain is the name 
given to the northern part of the ridge which is the highest point, its 
elevation being about 900 feet above sea-level and about 150 feet above 
Salisbury. Similar but less elevated portions of the ridge are locally 
known as Phillips Mountain, 6 miles nearly south of Salisbury, and 
Powlers Mountain, which forms a part of the extreme southwest exten- 
sion of the ridge, about 9 miles southwest of Salisbury. The area is fur- 
ther located between the middle and southeastern portions of the County. 

Over many parts of the ridge, especially Dunns Mountain proper and 
Phillips Mountain, the granite is exposed above the surface in the form 
of huge boulders 10 to 30 feet high and proportionately large in the other 
dimensions (see Pig. B, PI. X, and Fig. A, PL XI). At other points, as 
on the steeper slopes and near the top, the loose residual decay has been 
stripped from the surface exposing large and continuous areas of the 
hard and bare rock surface (see Fig. B, PI. XI). At still other places 
where the ridge character is less pronounced, large and continuous flat- 
surface areas of the hard and nearly fresh rock are exposed similar to 
that of the steeper slopes. Over the intervening areas nearly fresh gran- 
ite outcrops in smaller areas but the rock is mostly overlaid by a variable 
depth of residual decay, including soil, from one to 10 feet, which on 
account of the slope can be easily stripped, in most cases, when desired. 
In many places over the ridge the exposures of the granite are sufficiently 
large to yield immense quantities of the stone without stripping. 

The granite ridge roughly parallels the main line of the Southern Rail- 
way on the west, and at no point is it distant therefrom more than 4 
or 5 miles. The Yadkin Railroad, a branch of the Southern, extending 
between Salisbury and Norwood in Stanly County, crosses the ridge just 
south of Dunns Mountain proper at Granite Quarry station, making it 
practicable to build switches and open quarries over almost any part of 
the ridge. 

As regards color, two distinct and important grades of the granite 
occur which are quarried over parts of the ridge, namety, a very light 



102 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

gray, nearly white; and a decided pink or flesh colored stone. As shown 
below, this differentiation is based entirely on color since both the pink 
and the gray granite have identically the same texture and mineral com- 
position and are closely similar in other less important particulars. Again, 
this difference applies in color only to the northeast half of the ridge, a 
distance of some 5 or more miles. From Phillips Mountain, near the 
village of Faith, southwestward, the granite of the ridge is all decidedly 
of the very light gray nearly white color, with none of the pink shade 
indicated. 

Since the color and texture as well as the other properties of the pink 
granite make it a most desirable stone for certain grades of work, in- 
quiry into the quantity of this grade of the granite is of prime import- 
ance. Field study early developed the fact that the possible relations 
existing between the pink and the gra} r granite bore directly on the 
problem and accordingly three possibilities were suggested: First, that 
the pink color is a superficial phenomenon; second, that the pink and 
gray granites represent different intrusions ; and lastly, that the 2 
colors are phases of the same rock-mass. 

In both the pink and the gray granite the color is imparted by the 
feldspathic constituent, since the subordinate amount of the ferro- 
magnesian mineral, biotite, present in the rock, exercises practically no 
control over the color. That the pink color is not a superficial phenomenon 
is shown first by the fact that in those openings from which the pink 
granite has been quarried the color is uniform for the entire depth of 
working. Secondly, that over those portions of the ridge where the pink 
and the gray granite occur, having microscopically the same texture and 
mineral composition, and otherwise the same megascopically, no valid 
reason offers why, if the pink granite were a superficial phenomenon, it 
does not extend to all parts of the surface rock, rather than to certain 
areas, since similar conditions obtain for all portions of the ridge super- 
ficially, where the pink arid gray rock are associated. It is true, however, 
that over all parts of Dunns Mountain proper, the granite shows more 
or less of a pronounced pinkish tone, grading further south into the 
light gray colored rock without appreciable trace of the pinkish tone 
evident. The pink granite extends at intervals as far south as the village 
of Faith where several openings have been made in it; but beyond this 
point southwestward the granite is entirely of the light gray color. Be- 
tween Dunns Mountain proper and the village of Faith most of the rock 
is light gray, although several quarries have been worked within these 
limits in the pink granite (see PI. XVI, A and B). 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XI 




A. BOULDER QUARRY ON PHILLIPS MOUNTAIN, I MILE SOUTHWEST OF FAITH, ROWAN COUNTY. 




BARE SURFACE EXPOSURE OF GRANITE ON THE NORTHEAST SLOPE OF DUNNS MOUNTAIN, 
ROWAN COUNTY. 



THE VARIETIES OF BUILDING STONES. 103 

The entire field evidence is against the possibility that the pink and 
the gray rock represent separate intrusions. Not a single fact from 
careful field study favors such an hypothesis, but on the contrary the field 
evidence is conclusively against such. Neither does there seem to be 
any evidence favoring the possibility of a process of segregation from the 
cooling magma, whereby the one colored rock was differentiated from 
the other, such as has been observed at times in some granite masses. 

The possibility which seems to be the most plausible and the one to 
which the facts more nearly conform is that the pink and the gray 
granite are phases of the same rock. Where observed by the writer, the 
transition at every point from one color to the other is a more or less 
gradual one, and marked at no point by an abrupt or sudden change in 
color. Not only is there a gradual blending of colors in the two but no 
difference in structure, texture and mineral composition is developed 
from microscopic study, but the two differently colored rocks are identical 
in all respects save that of color. The feldspar content, which controls 
or conditions the color of the rock, indicates practically no appreciable 
difference between the pink and the gray granite, so far as revealed by 
the microscope; but the same species in nearly the same proportions are 
shown in all the thin sections examined of the differently colored rock. 
Why the feldspar contained in the granite at one point should be en- 
tirely pink; and nearby, through a gradual change is nearly white with- 
out trace of the pinkish tint indicated, has not yet been definitely de- 
termined for this area. 

On the basis that the two colors represent phases of the same rock, 
no rule can be laid clown for determining how much of either colored 
rock may be looked for in the granite boss, for variation in color may 
be expected to take place either vertically or laterally, or in both direc- 
tions. In this particular area the rock actually exposed to view over 
the ridge indicates considerably a preponderance of the light gray granite 
including much of the mixed pink and gray colored stone over that of 
the pronounced pink color. While the quantity of the pink granite is 
much less than that of the gray, shown by surface exposures and open- 
ings, conditions point to a very large supply of the pink granite. 

The light gray granite is equally strong and durable as the pink gran- 
ite, but much less desirable for a high grade of building or monumental 
work. 

The granite has been extensively quarried in many places over the 
ridge, and it has had a wide usage in nearly all grades of work in which 
granite is used, both in and out of the State. Large quantities of it have 



104 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

been and are still being quarried and worked into flagging and curbing 
for street purposes. Quarrying on the ridge dates back many years prior 
to the Civil War, and the large number of openings made over many of 
its parts may be grouped as follows, beginning at the extreme northeast 
end of Dunns Mountain and extending southwestward therefrom: 
I. Quarries on the north slope of Dunns Mountain. 
II. The Dunns Mountain (McCanless) quarries. 

III. The Eowan Granite Company's quarries. 

IV. The Balfour Quarry Company's quarries. 

V. The Consolidated Granite Company's quarries. 
VI. The Phillips Mountain quarries. 
VII. The Powlers Mountain quarries. 

Numerous minor openings not included in the above list have been 
made in many places over the ridge, but practically none of the stone 
has been quarried from any of them, hence they are not considered under 
the list of quarries. The detailed characters and the desirability of the 
stone over the ridge are best brought out in the description of the in- 
dividual quarries treated below. 

QUARRIES ON THE NORTH SLOPE OF DUNNS MOUNTAIN. 

About 4 miles east of SaKsbury a number of openings have been 
made on both sides of the Stokes Ferry road in the granite on the north 
slope of Dunns Mountain proper. These include several openings 
grouped closely together directly on the north side of the road made in 
boulder outcrops on the Crawford place; and the openings made in the 
steep northeast slope of Dunns Mountain proper, on the south side of 
the road, and separated from the Crawford openings by a distance of 
about 400 yards. 

Two openings on the Crawford place from which some stone has been 
quarried are made in huge boulder outcrops of a pronounced pinkish- 
gray granite. The boulders attain a height of from 10 to 30 feet 
and are proportionately large in other directions. Variation in color of 
the fresh granite is from decidedly pink to light gray, nearly white, with 
more or less mixed pink feldspar present in all of the stone. As a rule, 
the sap or partially decayed and discolored granite is very thin on the 
boulders. The feldspars of the partially decayed rock are white and 
opaque without luster, from kaolinization, and slight iron staining occurs 
from the partial leaching and alteration of the biotite. 

Two sets of joints cut the rock at rather wide intervals, which strike 
approximately X. 50° E., and N. 25° W. Large dimension stone can be 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XII 




A. DUNNS MOUNTAIN GRANITE COMPANY S QUARRY, EXPOSING FRESH AND DECAYED GRANITE. 




B. QUARRY NO, 2 OF THE ROWAN GRANITE COMPANY, 4^ MILES SOUTHEAST OF SALISBURY. 



•V 



THE VARIETIES OF BUILDING STONES. 105 

readily quarried. Veins, dikes and segregations do not occur in the rock, 
nor are any injurious minerals indicated. The rock is of uniform 
medium texture, containing a very subordinate amount of the dark sili- 
cate biotite, which almost entirely fails in some places. The granite in 
these openings exhibits good working qualities and it is a desirable 
stone for most uses made of granite. The microscopic characters 
of this rock are brought out in the description given below of the granite 
on the north slope of Dunns Mountain proper, 400 yards further south, 
which is identically the same rock. 

The north slope of Dunns Mountain proper exposes a bare, steep ledge 
of the granite more than 100 feet long and wide, which has been 
prospected along the foot and the middle portions of the slope (see Fig. 
B, PL XI). As indicated in the openings, the sap or partially discolored 
surface rock rarely exceeds a foot in thickness and the fresh granite is 
quite uniform in both color and texture. The summit of the mountain 
rises considerably over 100 feet above the level of the surrounding plain, 
with large areas of bare ledge and huge boulder exposures of the granite 
over the north, east and south slopes of the mountain. Some of the 
largest boulders are more than 30 feet high and proportionately large 
otherwise (see Fig. B, PI. X). On top of the mountain, similar ex- 
posures of the granite are seen. Over most of the mountain, including 
the summit and slopes, the granite is covered by a sufficient depth of 
loose residual decay to support a moderately thick growth of trees and 
smaller plants. The Yadkin Kailroad, a branch of the Southern, crosses 
the ridge about one mile south of this point. 

Over the summit and north slope of the mountain pronounced shear 
zones of crushed and laminated rock of very narrow width, not exceeding 
2 feet, and spaced at wide intervals, are developed in the granite. 
These zones follow or are coincident with the direction of the jointing 
which strikes X. 60° -70° E. Strike of the shear zones on top of the 
mountain at the picnic grounds is X. 55° E. The surfaces are usually 
slickensided and coated with a thin veneer of a yellowish green mineral 
substance, which is in part epidote. 

The rock is a pronounced flesh-colored pink granite of a mixed pink 
and gray tint, and of medium texture. Here, as over all parts of the 
ridge, the rock in the exposures shows a moderately developed schistose 
structure resulting from pressure-metamorphism. It is a beautiful gran- 
ite capable of a high polish and possesses good working qualities. Small 
grains and crystals of magnetite are distributed through the rock in 
places, and sometimes pyrite; more or less epidote is developed at times 
as a secondary product from partial alteration. The granite is a very 



106 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

desirable one for general building and other purposes, and dimension 
stone of any desirable size can be easily quarried. 

Microscopical Examination. — Under the microscope thin sections of 
the rock show an aggregate of feldspar and quartz with no dark bisilicate 
as an accessory. Finely striated acid plagioclase may equal or exceed in 
quantity the potash feldspars. Microcline is present only in subordinate 
amount. Crushing and recrystallization from intense dynamic forces are 
pronounced in the thin sections, indicated in finer mosaics of the quartz 
and feldspar bordering the larger individuals and filling the interstices. 
The laths of plagioclase are fractured and broken and, in some instances, 
bent, with irregular fractures and strained shadows common to the other 
constituents. Carlsbad twinning is common among some of the feld- 
spars. Scattered grains of magnetite and an occasional garnet are noted 
through the sections. 

A small opening is made near the foot of the west slope of the 
mountain, about 300 yards southwest of the north slope, from which a 
very small amount of the stone has been quarried. The granite is iden- 
tical with that described above both megascopically and microscopically. 
Small grains of magnetite are distributed through the rock. 

A chemical analysis of this rock, as given by Lewis 30 shows the stone 
to be unexpectedly high in silica. The specimen analyzed was obtained 
from an opening at the foot of the steep bare slope on the north side of the 
mountain, and possibly does not represent the general average: 

Analysis of pink granite, Dunns Mountain. 

Si0 2 75.14 

AL0 3 



a} 16 - 10 

MnO Trace 

MgO 0.04 

CaO • 0.93 

Na 2 5.82 

K 2 2.57 

Loss on ignition None 



Total 100.60 

THE DUNNS MOUNTAIN (MCCANLESS) GRANITE QUAERIES. 

This property includes 452 acres, located 4J miles southeast of Salis- 
bury and less than a half mile north of Granite Quarry station on the 

30 Lewis, J. V., Notes on Building and Ornamental Stone, First Biennial Report, N. C. 
Geol. Survey, 1891-1S92 (1893), p. 89. 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XIII 




ROWAN GRANITE COMPANY S QUARRY, 



NEAR THE YADKIN RAILROAD, 
SALISBURY. 



MILES SOUTHEAST OF 



THE VARIETIES OF BUILDING STONES. 107 

Yadkin Railroad. It extends from the base of Dunns Mountain proper 
to within 400 yards of the above named station on the railroad. A total 
of about 45 openings, large and small, are reported made over this prop- 
erty, most of which are in the nature of prospect openings and from which 
little or no stone has been quarried. 

The principal quarrying on this property has been confined to three 
large openings, which were being worked during the summer of 1903. 
The average dimensions of the largest openings are 267 feet long by 100 
feet wide and 30 feet deep. The sap or partially decayed granite exposed 
in this opening will average 12 to 14 feet thick, as shown in A of PI. 
XII. The largest dimension stone shipped from these quarries averaged 
14 feet long by 6 feet wide by 3 feet thick. One hundred pieces, each 6 
by 8 by 2 feet in size are reported to have been shipped to Reading, Penn- 
sylvania. Results of tests of this rock for road material are given on 
page 266. 

A spur track is operated between the quarries and Granite Quarry 
station on the Yadkin railroad. The equipment includes steam hoister 
and traveling cranes, derricks and drills, all of steam patterns. A num- 
ber 3 rock crusher, having a capacity of 300 yards of stone per day, is 
equipped and operated at the quarries for utilizing the quarry waste for 
road macadam and ballast. The principal use made of the stone has been 
in buildings and in the shape of blocks and curbing for street purposes, 
and as macadam and ballast.' It has been shipped for use to various points 
in the Carolinas, Virginia and Georgia, Reading, Penna., and Washing- 
ton, D. C. 

Two principal sets of joints intersect the granite in the large open- 
ings, striking N". 30°-40° W., and 1ST. 15°-20° E. Both sets of the planes 
are slickensided, and they are spaced at sufficiently wide intervals to ad- 
mit stone of almost any size blocks being quarried. What appears to be 
a segregation-shear zone of about 150 feet in width is observed in one 
of the openings, composed of dark gray augen-gneiss alternating with 
bands of nearly white granite two or more feet thick, having as nearly 
as could be determined a north-south trend. No injurious minerals nor 
blemishes were observed in any of the rock of the McCanless openings. 

The rock is a uniformly light gray granite of medium texture and of 
excellent working qualities. The feldspars assume a pinkish tone in 
places, which imparts more or less of a pinkish gray color to the rock, 
but the pink color is not intense enough nor sufficiently extensive, so far 
as prospecting on this property indicates, to warrant the quarrying of a 
separate grade of pink granite. The color and texture of the rock are 
quite uniform and the stone is a very desirable one for most pur- 



108 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

poses for which granite is used, especially as a general building stone. 
The rock is hard, firm and lively in appearance and it works well under 
the hammer. It takes a good polish and is susceptible of fine carved 
work, as displayed in some specimens of the carved stone at the quarries 
ready for shipment in July, 1903. 

THE ROWAN GRANITE COMPANY'S QUARRIES. 

The quarries of the Eowan Granite Company are located within a few 
hundred yards of Granite Quarry station on the Yadkin Eailroad and 
about 4-J miles southeast of Salisbury. Some 12 to 15 openings are made 
in different places over the 300-acre tract owned by this company. The 
two largest openings are within 200 yards of each other in a X. 30° E. 
alignment, and in size will average about 200 feet long by 150 feet wide 
and worked to an average depth of 32 feet. PI. XII, Fig. B, and PI. 
XIII, are views of these quarries. Dimension stones weighing 70 to 100 
tons each were being quarried from the southwest opening, quarry num- 
ber 2, in the summer of 1903, to be used in the construction of a dam 
across the Yadkin Eiver (see PI. XIV). 

Jointing in a number of directions breaks the stone into polygonal 
blocks of many different sizes, but while the planes intersect the rock at 
varying intervals, they are usually spaced far enough to permit blocks 
of almost any dimensions being quarried. Variation of a few degrees is 
indicated in the jointing in the different openings. Measurements made 
of the jointing in the principal openings on this property gave the fol- 
lowing results : 

X. 80° E. X. 25° E. X. 70° W. 

X. 65° E. X. 20° E. X. 50° W. 

X. 45° E. X. 15° E. X. 45° W. 

X. 40° E. X. 10° E. X. 40° W. 

X. 35° E. 

In the two largest openings the jointing indicated the following direc- 
tions in the strike : 

Quarry Xo. 1. X. 40° E., and X. 40° W. 
Quarry Xo. 2. X. 35°-45° E., and X. 45°-50° W. 

The stone quarried by this company is a light gray granite, more or 
less speckled in places with a pinkish feldspar, not sufficiently pink in 
color nor uniformly distributed through the rock to influence appreciably 
or modify the light gray color, except at very close range and by close 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XIV 



/ 




ROWAN GRANITE COMPANY S QUARRY, SHOWING THICKNESS OF GRANITE SHEETS THAT ARE CLEAVED 

AND QUARRIED. 



THE VARIETIES OF BUILDING STONES. 109 

scrutiny. The stone possesses good working qualities and dresses well 
under the hammer, and it is well suited for the various uses made of it. 

The granite has been used as a general building stone, for street 
purposes in the form of curbing and blocks and to a slight extent in 
monumental stock. Also a large quantity of ballast is reported to have 
been crushed and shipped from the quarries. It has been shipped for 
use to Washington, D. C, and to the most important points in Virginia 
and North Carolina, and to a limited extent to a few other States. 

The equipment at these quarries is very extensive and is entirely 
modern, which admits of the ready and easy handling of the stone. A 
No. 6 Gates rock crusher is installed and operated at the quarries for 
utilizing the quarry-waste in the form of ballast and macadam for road 
and street purposes. Preparations for more extensive quarrying and the 
enlarging of the equipment were being rapidly made in July, 1903. The 
installation of an adequate engine and dynamo for operating a 20-ton 
overhead electric traveler was then under way. At that date the power 
plant was expected to be completed within 3 months. 

In the 2 large openings, quarries Nos. 1 and 2, the granite shows in 
places an advanced stage of decay, varying in depth from the surface 
downward, from 5 to 6 feet and occasionally more. In quarry No. 1 
the granite at one point is completely decayed to a depth of more than 
10 feet (see Fig. A, PL XVII). The weathered product consists of light 
red and gray granitic sand and clay, that can be easily removed with the 
pick and shovel. As indicated in the figure, the weathering of the granite 
at this point is after the manner of the typical concentric form, into 
layers of mixed red and light gray colors. The entire mass is reduced 
to a soft siliceous clayey material, in which the layered or shelly structure 
is completely preserved. 

In quarry No. 2, oxidation seems not to have progressed quite so far 
in the process of weathering, and the decayed product on the northwest 
side is a light gray colored mass of partially hard and soft decay, in 
which the individual minerals of the fresh granite are easily dis- 
tinguished. This depth of decay is somewhat extreme and does not ex- 
tend over all portions of the 2 quarries. As a rule, hard and firm 
nearly fresh granite, only slightly discolored to a depth of a few inches, 
characterizes the principal exposures of the granite on this property; 
though not infrequently white, lusterless, chalk-like granite showing more 
or less discoloration from the liberated iron oxide of the mica, and due 
largely to the advanced kaolinization of the feldspars, reaches depths of 
many feet. Boulders split by blasting are seen to be discolored from 
weathering frequently 5 or 6 feet from the surface (see PI. XV). 
9 



110 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

THE BALFOUR QUARRY COMPANY'S QUARRIES. 

The quarries of the Balfour Quarry Company are located within less 
than a half-mile south of the Rowan Granite Company's quarries, near 
Granite station on the Yadkin Railroad; about 5 miles N. 20° W. of 
Salisbury and 2 miles northeast of Faith. Two openings have been 
made near together, the smaller one of which is hardly more than a 
prospect and is made in light gray granite of the same color, texture and 
composition as that quarried by the Rowan Company described above. 

The principal quarry or opening of this company is in a beautiful pink 
granite known as the Balfour pink granite quarry. The opening is made 
in a ledge exposure of the granite having a slope of about 25 degrees. 
Practically no soil — residual granite decay — covers the granite except 
on the east side, where slight stripping is necessary before quarrying. 
The sap or partially discolored rock is very thin over most of the ex- 
posure except on the southeast side of the opening where the partially 
discolored rock attains a thickness of several feet from the surface down- 
ward. On the north side of the opening entirely fresh rock begins 
practically at the surface. Some weathering from oxidation resulting 
in a reddish discoloration of the rock, amounting to hardly more than 
a thin veneer, is observed along the jointed surfaces (see PL XVI). 

Two sets of vertical joints break the granite into large blocks striking 
N. 10° E., and 1ST. 70° W., and are spaced at sufficient intervals to .admit 
of quarrying dimension stone of almost any size. The jointed surfaces 
show slickensides. So far as quarrying operations have extended, in 
depth not exceeding 30 feet, the rock appears to be disposed in plates or 
sheets which vary in thickness from 2 to 10 feet, with a probable average 
of 8 feet. No veins nor dikes penetrate the rock in either of the open- 
ings, and the granite is entirely free from any injurious minerals. 

The rock is a beautiful pink granite of uniform color and texture and 
should prove to be an excellent stone for all purposes that require the 
best grades of granite. Its susceptibility of a high polish makes it a 
most desirable stone for monumental and decorative stock. The texture 
is medium-grained similar to that of the light gray granite. The ferro- 
magnesian constituent, biotite, is very sparingly developed in the rock; 
and the feldspathic constituent, uniformly colored pink, is evenly dis- 
tributed through the stone. The working qualities of the rock are ex- 
cellent and dimension stone of any size is easily quarried. 

Microscopical Examination. — A thin section of the fresh rock collected 
from the pink granite quarry showed under the microscope a complexly 
interlocking aggregate of feldspar and quartz. The effects of shattering 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XV 




THE VARIETIES OF BUILDING STONES. Ill 

and recrystallization by dynamic forces are strongly emphasized in the 
section. The larger feldspar individuals are all bordered by a fine- 
grained mosaic, while the quartz occupies distinct and well-defined areas 
between the feldspars as a very fine aggregate of interlocking grains in 
which similar grains of feldspar may or may not occur. The plagioclase 
laths are broken in some cases, and fractures and undulous extinction 
characterize the other minerals to a large degree. 

The feldspathic constituent is composed of orthoclase and a nearly 
equal amount of stout, finely striated acid plagioclase, with only occa- 
sional grains of microcline. The feldspars are filled with closely crowded 
dust-like particles of a brownish red color. No dark bisilicate is in- 
dicated in the section examined. Occasional grains of titaniferous iron 
oxide are scattered through the section, more or less altered peripherally 
into a clear and colorless titaniferous by-product. Small, almost micro- 
scopic grains of pyrite occasionally occur, but seem to have no deleterious 
effect. 

Efficient modern equipment, including the necessary tools for polish- 
ing, is being installed at the quarry for quarrying and handling dimen- 
sion stone of any desirable size. Stone from this quarry was used in 
the building of the Catholic University in Washington, D. C. This grade 
of pink granite is in much demand in Chicago and other northern and 
central cities for use as monumental stock. This granite will be used in 
the construction of the new Municipal court building in Washington, 
D. C. During the summer of 1905 the grade of light, nearly white 
granite was beirg quarried chiefly for use in paving only, and was being 
shipped principally to Cincinnati, Ohio. 

THE CONSOLIDATED GRANITE COMPANY'S QUARRIES. 

The Consolidated Granite Company's property includes 151 acres 
located 5-§ miles south of Salisbury and bordering the northern 
and eastern limits of the village of Faith.. It is distant If miles from 
the nearest railroad point. A survey of the route from Yadkin Rail- 
road and the quarries has been made relative to building a spur track 
for hauling the stone. This company had only assumed control of the 
property a short time previous to July, 1903. Extensive prepara- 
tions were then being made for installing all the necessary modern 
equipment for the quarrying and handling of dimension stone; the 
erection of crushers for the utilization of the quarry- waste ; and the 
necessary machinery for the proper shaping of granite for the various 
uses made of it. 



112 BUILDING AND OENAMENTAL STONES OF NORTH CAROLINA. 

Prior to the Consolidated Company's assuming control of the property, 
considerable stone had been quarried from a large number of openings 
over the tract at intervals dating back some years prior to the Civil War. 
Numerous shipments of the stone were reported to have been made dur- 
ing the early period of quarrying to various points in Virginia and North 
Carolina. Large areas of the hard and moderately fresh granite are ex- 
posed over the tract, requiring little or no stripping for quarrying. The 
sap or partially decayed granite from weathering is usually thin on these 
exposures and is easily removed with the first raise. Where covered by 
the loose residual decay the covering is, as a rule, of slight depth and 
can be quite easily removed. Except in a few places, the slope of the 
ledges is sufficiently steep to afford almost any reasonable depth of 
quarry-face. 

Two grades of granite have been quarried in different places on this 
tract ; a light gray granite of the same texture and color as that quarried 
near Granite Quarry station by the Eowan Granite Company, and a pink 
granite of the same depth of color and texture as that quarried farther 
north on the ridge by the Balfour Quarry Company. Numerous open- 
ings have been made in both the pink and the gray stone, which affords 
some basis for judging of the extent of the two differently colored gran- 
ites. So far as revealed in the openings, the pink granite is in large 
quantity on this tract, and is quite uniform in both color and texture to 
the entire depth of the openings in which it is exposed. The gray gran- 
ite in which a sprinkling of pink feldspars occur in many places makes 
up the bulk of the granite exposed over the tract. The two colors, pink 
and gray, are observed grading more or less gradually into each other, 
in a number of places on the property. 

Vertical jointing is quite strongly developed in several directions in 
the various openings, with the planes usually spaced at intervals suffi- 
cient to allow the quarrying of dimension stone of any desirable size. 
Measurements of the joint-planes in the numerous openings over the 
tract gave the following results: 

N. 80° E. N. 50° W. . N.-S, E.-W. 
N. 40° E. N. 40° W. N.-S. 
N. 10° E. N. 30° W. 

The directions of the principal jointing are those which lie in the north- 
east and northwest quadrants. No veins, dikes, nor segregation areas 
were observed in the granite at any point; nor were there any injurious 
minerals contained in the stone likely to cause discoloration on exposure, 
so far as the field examination disclosed. 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XVI 




A. QUARRY OF THE BALFOUR QUARRY COMPANY IN THE PINK GRANITE OF DUNNS MOUNTAIN, 

ROWAN COUNTY. 




'3. 



CUTTING SHED OF BALFOUR QUARRY COMPANY WITH . LARGE BLOCK OF PINK GRANITE. 



THE VARIETIES OF BUILDING STONES. 113 

Megascopically, the rock is in all respects similar to that quarried by 
the Rowan Granite Company and the Balfour Quarry Company described 
above, near Granite Quarry Station on the Yadkin Railroad. The tex- 
ture, color and working qualities are apparently the same as for the 
granite at the above locality, and it is equally as desirable a stone for all 
purposes. 

Microscopical Examination. — Microscopically, thin sections cut from 
specimens of the pink and the gray granite collected on this property are 
essentially identical. Under the microscope the thin sections show an 
aggregate of interlocking feldspar and quartz in which lie occasional 
shreds of biotite. Orthoclase, with good cleavage development, is the 
predominant feldspar with plagioclase equal or nearly equal in amount, 
while microcline is only sparingly developed. Extensive mechanical 
deformation is indicated in the thin sections, of the same nature as 
described above for the Balfour Quarry. The feldspar individuals are 
frequently broken and the parts separated and cemented by veinlets or 
stringers of a quartz mosaic. This is especially true of the plagioclase 
and to a less extent of the orthoclase. Twinning on the Carlsbad law is 
noted and dust-like inclusions of reddish brown color crowd the feldspar 
individuals. Biotite is only sparingly distributed through the sections 
having the usual color and strong absorption and characterized usually by 
the same inclusions. Scattered grains of magnetite occur with a few 
minor accessories which exercise no effect on the rock. 

In July, 1903, stone was being quarried to supply orders from San 
Francisco, Cal. ; Jacksonville, Fla., and Indianapolis, Ind., for city work. 
Its uses for various purposes is reported to have been very extensive over 
the State. 

THE PHILLIPS MOUNTAIN QUARRIES. 

Phillips Mountain is the name given to a very large, low, conical peak, 
located about one mile southwest of the village of Faith, which marks 
the extension southwestward of the Dunns Mountain granite ridge. It 
is distant some 3 or more miles from the nearest railroad point. The 
granite is exposed over the surface of the peak in the form of huge 
boulder masses in which very many quarries have been worked and many 
of the boulders entirely or partially worked ofT. (See Fig. A, PI. XL) 

The stone is a very light gray, nearly white biotite granite of medium 
texture and having excellent working qualities. The color and texture 
are quite uniform over the entire area and the granite is a very desirable 
one for nearly all grades of work. Blocks of almost any size can be 



114 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

readily quarried. The stone works well under the hammer and it is 
quite free from blemishes and injurious minerals of any kind. 

A number of openings were being worked during the summer of 1903 
and most of the stone quarried was being worked into curbing for street 
purposes. The rock is hard and tough, firm and compact, and lively in 
appearance and it should receive wide favor both as a general building 
and street stone. 

The sap or partially discolored granite is usually thin on the boulders 
and, as a rule, occasions but slight waste in quarrying. In many in- 
stances, however, weathering has penetrated deeper from the surface, 
especially along some of the jointed surfaces, and is for the most part of 
the normal kind described above. A peculiar form of weathering of 
the granite which is rather common over many parts of the ridge and 
frequently met with in the exposures over Phillips Mountain, is described 
below. 

Microscopical Examination. — Thin sections cut from specimens of the 
granite collected from the principal openings on the peak indicated 
under the microscope a medium textured mosaic of interlocking feldspar 
and quartz, through which is distributed very subordinate biotite. Plagio- 
clase is nearly equal to or is quite as abundant as the potash feldspar. 
Orthoclase among the potash feldspars usually predominates, although 
microcline may be equal to it in amount in some sections. Feldspar 
intergrowths as microperthite are distributed through the sections. Dust- 
like inclusions occur in some of the feldspar and rarely Carlsbad twin- 
ning is developed. Biotite of the usual color and absorption is sparingly 
distributed through the sections and is either partially or entirely altered. 
Scattered grains of magnetite and a few other microscopic accessories 
are noted. 

Effects of intense shattering and crushing of the feldspar and quartz 
grains from dynamic forces are conspicuously shown in the finer mosaics 
of these two minerals, and in the strain shadows and fractures in the 
larger individuals. The plagioclase individuals are frequently broken 
across the parts separated, and in some instances bent and curved. 

Examination under the microscope of sections cut from some of the 
partially weathered and discolored granite indicates much iron oxide 
staining from the alteration and leaching of the biotite, while the feld- 
spars indicate, as a rule, only moderate alteration. 

THE POWLEES MOUNTAIN QUARRIES. 

The low doming-mass of granite 3 miles southwest of the village 
of Faith and 9 miles southwest of Salisbury, locally known as Powlers 
Mountain, marks the southwest extension of the granite ridge in Rowan 



THE VARIETIES OF BUILDING STONES. 115 

County. The nearest railroad point is distant several miles from the 
area. The granite is exposed in more or less irregular bummocky sur- 
faces, bare of loose residual decay over much of the area, but covered in 
places by a variable depth of the weathered product. Its greatest eleva- 
tion is less than 100 feet above the surrounding plain and its slopes, while 
not entirely uniform, are somewhat gradual and admit of quarries being 
opened in ledges that would afford almost any desirable depth of quarry- 
face. 

Several openings were made in places on the slopes of the doming- 
mass many years ago, when the surface raises were worked off. Exami- 
nation of these ledges shows the rock to be considerably weathered, though 
still fairly hard and firm. The feldspars show a dead, lusterless ap- 
pearance from kaolinization, and entirely fresh hand specimens of the 
rock could not be obtained. Two sets of joints which strike N". 20° E., 
and N". 70° W., break the granite into blocks of different sizes. 
The N". 70° W. set of joints is especially well developed and cuts the 
granite more frequently and at closer intervals than the former. As a 
rule, the intervals at which the joint-planes penetrate the rock are far 
enough apart to admit of blocks of almost any size being quarried. 

The rock is a light gray granite very largely composed of feldspar and 
quartz, with very subordinate biotite. It contains no injurious minerals 
and is of medium texture. The size of the component grains in the rock 
is practically the same as that for the granite farther north on the ridge, 
but the mineral individuals do not appear to interlock in the same man- 
ner and the rock presents a somewhat different textural appearance. The 
difference may perhaps be less emphasized in the fresh rock. 

About 300 yards east of Powlers Mountain proper an opening 
has been made in an extensive flat-surface exposure of a dark gray 
biotite granite of medium texture. Stone was quarried from the open- 
ing more than 30 years ago, when a moderate amount of stripping 
was done. The rock is entirely uniform in color and texture ; contains 
a larger quantity of biotite than the average granite of the ridge and is 
therefore darker in color. It appears to be a desirable stone with 
fair working qualities, and is free from injurious minerals or 
blemishes of any kind. Dimension stone of any size can be readily quar- 
ried. While scarcely more than the surface raises were worked off from 
portions of the exposure, the rock appears hard and fresh and greatly 
more resistant to atmospheric agents than the rock in the ledges opened 
on the slopes of Powlers Mountain. 

Microscopical Examination. — Microscopically, a thin section of the 
rock from this opening indicated an aggregate of feldspar and quartz, 



116 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

which shows the same extreme effects of mechanical deformation as the 
thin sections of the granite farther north on the ridge. The finer 
mosaics of feldspar and quartz resulting from crushing are perhaps not 
so abundantly developed, but strain shadows and fractures are charac- 
teristic, and the broken parts of the feldspars are frequently bent and 
curved. The section shows some iron stained spots here and there re- 
sulting from the complete alteration and leaching of the biotite and 
probably some pyrite. Occasional grains of magnetite occur. Plagio- 
clase nearly equals in quantity the orthoclase with microcline sparingly 
distributed. 

THE JOSEY-BOGER PROPERTY. 

Several miles S. 20°-30° W. of the village of Faith very large and 
continuous flat-surface exposures of a thinly schistose saccarhoidal gran- 
ite-gneiss occur on the adjoining properties owned by Josey and Boger. 
As much as 25 acres and more of the exposed rock were observed in a 
single continuous outcrop, which was bare of any loose residual decay. 
Between the outcrops, the rock is mantled to some depth with the loose 
residual decay. A number of very small prospect openings have been 
made in several exposures of the granite at different places. 

The rock is composed of a very white matrix of fine granular quartz 
and feldspar, speckled with small rounded areas of aggregates of black 
biotite, distributed at intervals and occupying distinct places, which im- 
part a decided spotted appearance to the stone. It is a very thinly 
schistose rock and when broken in the direction of the schistosity the 
dark mica areas are of knife-edge thickness, a result of pressure-meta- 
morphism. 

The strike of the schistosity is N". 10° E., and the rock is penetrated 
by a well developed set of E.-W. joints spaced at intervals of from 4 
to 12 and more feet. No veins, dikes, nor segregations were any- 
where indicated in the rock, and it is free from harmful minerals. The 
granite-gneiss is in contact with an extensive belt of diorite on the east 
side. At this locality the rock is more completely schistose than that of 
any other part of the granite ridge, indicating more the effects of pres- 
sure-metamorphism. The study of thin sections of the rock from dif j 
ferent parts of the ridge area is in full accord with the megascopic fea- 
tures as regards difference in the effects of extreme metamorphism. 

Microscopical Examination. — Thin sections of the rock from the Josey- 
Boger places show microscopically a completely interlocking fine-grained 
aggregate of feldspar and quartz, in which crushing effects from dynamo- 
metamorphism are unusually strongly emphasized. The quartz is almost 



THE VARIETIES OE BUILDING STONES. 117 

completely crushed into a very fine mosaic, occupying somewhat distinct 
areas, while in addition to the crushing and granulation of the feldspar, 
much of it is broken, bent and curved, and strain shadows are intensified. 
Plagioclase exceeds in amount the potash feldspar, and orthoclase greatly 
predominates over microcline. Biotite is into distinct areas of aggre- 
gates of the usual color and absorption and shows partial alteration. 
Very occasional small grains of magnetite are distributed through some 
parts of the sections. 

THE WOODLEAF GRANITE AREA. 

In the northwest corner of Eowan County numerous outcrops of biotite 
granite occur in and around Woodleaf, a station on the Charlotte-Wins- 
ton branch of the Southern Eailway, about 11 miles northwest of 
Salisbury. Small openings have been made in the granite exposures in 
different places and some of the stone has been quarried for local use. 

Near the northwest limits of the village of Woodleaf a small quantity 
of the stone has been quarried for local use from an opening made in a 
flat surface exposure of medium gray biotite granite of fine texture. The 
exposure is a small one and only a portion of the surface raise has been 
worked off. Very small segregrated areas or blotches of biotite are dis- 
tributed through the rock, which also has a slight schistose structure 
developed. Two sets of joints intersect the granite, striking 1ST. 20° E., 
and N". 60° E. Abundant small pyrite crystals are developed along the 
surface of some of the joint planes, but as a whole the rock seems to be 
free from this mineral. The granite is only suitable for use in the ordi- 
nary grades of work. 

Microscopical Examination. — Microscopically, a thin section of the 
rock reveals a very fine-textured biotite granite in which the principal 
minerals, feldspar and quartz, interlock in a very irregular and intricate 
fashion. The mineral grains are unequal in size, the larger ones dis- 
playing some effects of crushing peripherally, and the larger interstitial 
areas are filled with the finer, mosaic of feldspar and quartz. Plagioclase 
as single individuals entirely fails, and the feldspathic constituent in- 
cludes orthoclase and microcline, the former predominating, with abund- 
ant feldspar intergrowths in the form of microperthite. The feldspar is 
considerably altered, principally to muscovite. Biotite of the usual 
color and absorption is quite freely distributed through the section, 
though largely altered to a colorless mica, and there is a little chlorite, 
rutile and iron oxide. Muscovite as a secondary mineral, associated with 
the feldspar and biotite, is somewhat abundant. Micrographic areas of 
quartz and feldspar intergrowths are very common, and some epidote is 
noted. 



118 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

About one mile west of the village of Woodleaf the railroad has cut 
through in a number of places a biotite granite of the same color and 
texture as that described above. A dark basic eruptive dike, approxi- 
mately 300 feet wide and having a general northwest trend, penetrates 
the granite at this point. The same granite is again exposed in the 
shallow cuts along the railroad near the depot. In each of the cuts along 
the railroad exposing the granite, the rock manifests the effects of con- 
siderable weathering in the kaolinized, lusterless, feldspar and slight 
staining from the liberated iron oxide derived from the leaching of the 
biotite. The granite in the railroad cuts is further closely jointed, with 
several sets of planes breaking it into small blocks. The same granite 
but of porphyritic texture is exposed at the spring across the railroad 
from the depot. 

One mile east of Woodleaf Station, directly on the east side of Third 
Creek and the south side of the railroad, a small opening has been made 
in a pronounced schistose granite-gneiss from which stone was quarried 
for bridge piers along the railroad. The rock is a fine-textured granite- 
gneiss of good quality and is a desirable stone for the ordinary grades of 
work. 

Several other small openings are made in outcrops of the granite in the 
vicinity of Woodleaf. The granite is reported to be traced westward for 
a distance of 4 or more miles ; and eastward 3 miles from Woodleaf along 
the Yadkin Eiver at Cooleemee cotton mills, in Davie County, a similar 
granite is exposed from which stone was quarried for building the 
dam across the river at the cotton mills. 

In the cuts along the railroad just east and west of the depot at Wood- 
leaf, sharp contacts between the granite and the extensive belt of diorite, 
described below, are fairly well exposed, as indicated in B of PL V. 

THE SALISBURY PORPHYRITIC GRANITE AREA. 

Beginning about 2 miles northwest of Salisbury on the Wilkesboro 
road, is an extensive belt of coarse-textured, biotite, porphyritic granite, 
which can be continuously traced northwestward along the road by its 
residual decay, to a point about 8 miles from Salisbury. The porphy- 
ritic granite grades in many places along the road into an even-granular 
■facies of the rock of the same texture and composition as the groundmass 
of the porphyritic rock. Only at one point were exposures of the fresh 
rock observed, namely, about 3 miles northwest of Salisbury immediately 
on the road, where a small opening had been made and a very limited 
quantity of the stone quarried for road macadam. 



THE VARIETIES OE BUILDING STONES. 119 

The groundmass of the rock is a medium-textured biotite granite of 
moderately dark color, containing much biotite. The phenocrysts are 
composed of potash feldspar, usually idiomorphic in outline and develop- 
ing twinning on the Carlsbad law. As a rule, they are very large, vary- 
ing from two or more inches long by a half to one inch wide. They con- 
tain inclusions of the groundmass biotite and in one or two places a ten- 
dency toward orientation was indicated. 

The rock is deeply weathered, yielding a light gray granitic sand, 
rarely deeply colored from iron oxide staining. The large phenocrysts 
in a more or less kaolinized form are rather thickly strewn over the 
surface, and offer a very sure means of tracing the rock. These are 
sometimes split into smaller pieces along the cleavage directions, and in 
the shallow cuts along the road exposing sections of the decay. The par- 
tially weathered phenocrysts are observed distributed through the granite 
decay occupying exactly the same position in the decay as in the fresh 
rock. 

BASIC IGNEOUS ROCKS. 

Perhaps no county in the main granite belt of the State contains more 
extensive areas of igneous rocks of the basic types than Eowan. The 
principal types represented are diorite, diabase, and gabbro. Of these, 
diorite probably forms the most extensive areas. In one locality in the 
County gabbro is being quarried and used for monumental stock, and has 
already become favorably known in many of the towns over the State in 
this class of work. The extensive areas of some of the other basic types 
and the good qualities of the rock should bring them in favor for use in 
certain grades of economic work. 

Diorite. 

The rather extensive occurrence of this type of rock over some por- 
tions of the County renders it desirable to make some mention of it here. 
The most extensive area of diorite in Rowan County occurs in the north- 
west portion of the County. Beginning about 8 miles northwest of 
Salisbury along the Wilkesboro road, the easternmost extension of a 
very large area, of the diorite is observed in contact with the porphyritic 
granite described above. The diorite is continuously traced from this 
point westward along the roads to Barber Junction and Woodleaf sta- 
tions on the Charlotte-Winston branch of the Southern Railway; and 
northwestward into Davie County at the Cooleemee cotton mills. The 
area is traced farther westward into Iredell County where excellent ex- 
posures of the diorite are found in many places in the vicinity of Elm- 
wood. 



120 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Very sharp and well defined contacts between the diorite and the 
granite are observed in the railroad cuts to the east and west of Wood- 
leaf Station, and at no point studied by the writer do the 2 rocks grade 
into each other, but on the contrary the field evidence conclusively points 
to them as representing separate intrusions. The diorite shows marked 
variation in composition, color, and texture over the area. In color, 
variation is from a lighter colored rock in which plagioclase predominates 
over the hornblende, to a very dark colored rock composed largely of 
hornblende, with all gradations indicated between the 2 extremes. 
Naturally the variation in color i& controlled or conditioned by the 
variation in composition already noted. The texture is medium-grained 
becoming coarser or finer in places as the case may be. 

Microscopical Examination. — A large number of thin sections of the 
rock collected over all parts of the area show a typical diorite whose 
variation from place to place in the essential minerals, hornblende and 
plagioclase, is as stated above. Some of the sections show more or less 
quartz which in one or two instances is in amount sufficiently large to 
characterize the rock as a quartz diorite. The usual accessories are ob- 
served in the thin sections. 

A second but smaller area of diorite of the same character and show- 
ing similar variations occurs on the Josey place, 3 miles S. 20° W. of the 
village of Faith, and about 8 miles nearly south of Salisbury, on the 
southeast side of the granite ridge in this vicinity, described above. 

So far as the writer is aware no attempt has been made to quarry the 
diorite at any point in the County for any purpose, but it certainly forms 
a most desirable stone for road and street macadam, and it might be 
used to advantage in other classes of work. 

Gab or o. 

The only area of this rock noted in Eowan County occurs about 4 
miles south of Barber Junction, along the Charlotte-Winston Railroad, 
in the extreme western portion of the County. At this point very large 
boulder outcrops are exposed over a considerable area, and the rock is 
quarried for monumental stock. 

THE CONSOLIDATED GRANITE COMPANY'S (MCGALLIARD) QUARRY. 

This quarry is located about 4 miles south of Barber Junction,, 
within a short distance of the Charlotte-Winston branch of the Southern 
Railway, from which a siding is being built to the quarry. The rock was 
first opened about 4 years ago and has been continuously worked for 



THE VARIETIES OE BUILDING STONES. 121 

the past. 8 months, dating from July, 1903. It is worked exclusively 
for monumental stock, and shipments of the stone for this purpose 
are reported to have been made to Chillicothe, 0. ; Baltimore, Md. ; Wash- 
ington, D. C; Brooklyn, 1ST. Y.; Danville, Ya. ; Charleston, S. C; Shelby- 
ville, Ind. ; Ealeigh and Wilmington, KC. An order was recently placed 
for a, $5,000 monument to be erected from this stone in the cemetery at 
Winston-Salem. 

The openings are small and entirely confined to the huge boulders 
which have not yet been worked off. The rock is practically free from 
sap or partially discolored stone from weathering, and no waste is oc- 
casioned from this source. Blocks of any desirable size are readily quar- 
ried. The stone for its kind works and dresses well under the hammer 
and takes a very high and excellent polish. The contrast between the 
hammer-dressed and the polished surfaces is very striking, a feature 
which taken in connection with its other excellent properties makes it 
a desirable stone for monumental stock. Occasional small grains and 
crystals of pyrite and knife-edge veinlets or stringers of dark greenish- 
colored mineral occur in the rock, but are not present in quantity suf- 
ficient to in any wise detract from the excellent qualities of the stone. 

The. rock is of medium texture, dark gray, almost black, in color and 
contains considerable biotite distributed through it. It compares quite 
favorably with the well known " black granite " of Addison Point, Maine. 
Being somewhat harder and tougher than granite, it is less easy and 
accordingly somewhat more expensive to quarry. This quarry is owned 
and operated by the Consolidated Granite Co. of Winston-Salem, N\ C. 

Microscopical Examination. — Microscopic study of thin sections of 
the rock shows it to be a norite containing much biotite, composed of 
orthorhombic and monoclinic pyroxenes largely hypersthene, plagio- 
clase, a little orthoclase, some hornblende, a sprinkling of quartz, and 
titaniferous magnetite. 

The texture is intermediate between typical ophitic and granitic with 
a stronger tendency toward the former or diabase texture (see Fig. B, PI. 
II). The hypersthene is in massive, irregular, individuals without 
definite crystal outline, displaying the usual cleavage and strong pleo- 
chroism. The remaining p}Toxene is non-pleochroic and of very pale 
greenish color by polarized light. The strongly pleochroic -pyroxene 
shows very general alteration to the non-pleochroic variety of pale green- 
ish tone, accompanied by the separation of iron oxide in the form of 
minute black grains. In this form of alteration the center of the indi- 
vidual is fresh hypersthene surrounded by an outer portion of nearly 
pale greenish form. In addition to this form of alteration there is a 
fair sprinkling of secondary hornblende possessing all the characters of 



122 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

the primary compact form, for which there is no indication of a secondary 
origin. Still another form of alteration in the pyroxene is into a deep 
green fibrous mineral forming peripherally a fringe or border aronnd the 
original mineral. 

Much deep brown, strongly pleochroic plates of biotite are distributed 
through the thin sections and it is prominent in the hand specimens of 
the rock to the unaided eye. Abundant small grains and crystals of 
black iron oxide form inclusions in the pyroxene, biotite and feldspar. 
Plagioclase is abundant and is of the usual kind in such rocks, forming 
stout laths which, in many instances, display beautiful zonal structure. 

Boulder outcrops of the same rock, but of finer texture, are. traced 
over the surface on both sides of the railroad to within 2-| miles 
south of Barber Junction. A number of thin sections of the rock 
collected from various places over the area were studied microscopically, 
indicating essentially the same composition but of finer and distinctly 
granitic texture. Thin sections of specimens of the rock collected 1J 
and 2-J miles south of Barber Junction, respectively; and a half mile 
northwest of the quarry along the railroad, were characterized micro- 
scopically by an entire absence of biotite and only occasional secondary 
hornblende. The amount of magnetite is increased in all of the thin 
sections over that in the sections of the rock from the quarry . 

Diabase. 

Dikes of diabase are rather numerous over many parts of the County. 
Wherever they have been observed the rocks are very dark in color and 
usually fine textured, varying from olivine to olivine free diabase. Varia- 
tion in the width of the dikes is from a few feet to 100 and more 
feet, and they strike in a general northeast and northwest direction. 
The dikes of this type of rock are especially numerous in the north and 
northwest portions of the County in the vicinity of the Cooleemee cotton 
mills. The more important dikes of diabase noted in the County are 
listed in the table of dikes on page 184. 

DAVIDSON COUNTY. 

The southeastern half of Davidson County forms a part of the so- 
called " Carolina Slate Belt." The rocks comprise chloritic and argil- 
laceous schists with some altered, probably devitrified rhyolite, in which 
the flow structure is still apparent. Dikes of basic eruptive rocks of 
hornblendic composition intersect the schists in places. The strike of 



THE VARIETIES OE BUILDING STONES. 123 

the schists varies from N". 10° to 35° E., and in the dip the variation is 
from 'N. 40° W. to nearly vertical. 31 

Over the remaining portions of the County somewhat extensive areas 
of granite are found. Where examined, these belong without exception to 
the biotite type. They vary from massive to schistose in structure and 
from even-granular to porphyritic in texture, and are of gray color. The 
two textures represent different facies of the same granite-mass, as the 
porphyritic granite is found grading into that of even granular texture 
of the same mineral compositions. The porphyritic granite forms a 
very extensive area to the west of Lexington, the county-seat, and it is 
continuously traced westward across the Yadkin Eiver into Davie County 
as far west as Advance Station, where it forms the country rock over the 
western part of Davidson and the contiguous eastern portion of Davie 
County. 

The wide intervals at which outcrops of the massive and the schistose 
granites are found make it impossible to say whether the granites of 
schistose structure grade into the massive ones. Evidence from the de- 
cay of the two structural types is entirely lacking. The general appear- 
ance of the rocks in texture and mineral composition would indicate that 
the massive and schistose granites are structural phases of the same 
granite-mass for in the field the rocks are strikingly similar in all re- 
spects but structure. 

To the south, north, and west of Lexington the country rock in places, 
is a variable schist ranging from biotitic and sericitic to quartzitic in 
composition. Sharp contacts between the partially decayed schists and 
granites were observed in several places, and the relations between the 
2 rocks plainly indicate that the granites were of later date than the 
schists into which the former had been intruded. Dikes of basic com- 
position penetrating these rocks are mentioned below. 

The granites have nowhere been regularly worked in the County but 
some stone has been quarried from time to time from a number of places 
as needed to supply local demand. The openings are all small and are 
located in the vicinity of Lexington, the county-seat, where the rock has 
been principally used. 

LEXINGTON GRANITE AREA. 
THE CONRAD PLACE. 

About 1^ miles north of Lexington on Joseph Conrad's place, 
several small openings, near together, have been made in outcrops 

31 Nitze, H. B. C, Bulletin No. 3, N. C. Geol. Survey ^ 1896, pp. 60-74. 



124 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

of a dark gray, fine-grained massive biotite granite. The openings were 
first made about 1856 and the rock quarried was used in the court-house 
building in Lexington, and bridge piers along the Southern Eailway. 
The rock outcrops in the form of large boulders, fiat-surface masses, 
and ledges over some 40 to 50 acres of surface. 

The granite is quite uniform in texture and color and it contains no 
deleterious minerals. It should prove a desirable stone for general 
building and monumental purposes. The largest one of the openings 
does not exceed 50 feet square and is worked to a depth of probably 25 
feet. Some of the blocks quarried in 1856 and left at the opening are 
as fresh to-day as when first taken out. 

Microscopical Examination. — A thin section of the rock from the 
main opening on the Conrad place indicates microscopically a fine- 
grained biotite granite in which the mineral aggregates closely interlock. 
The feldspar consists of orthoclase and a little striated plagioclase, no 
microcline being observed. Twinning after the Carlsbad law is frequent 
and some alteration is shown in the feldspar. Biotite of the usual color 
and absorption is uniformly distributed through the section as shreds 
containing some inclusions and partly altered to chlorite, a colorless 
mica, and some epidote. Some rutile is associated with the biotite. 
Large stout prisms of apatite and small ones of zircon occur as inclu- 
sions. Small grains of magnetite are sparingly distributed through the 
section. 

THE FKTTTS PLACE. 

Less than one-half of a mile south of the Conrad openings, two small 
circular ones have been made in the same granite on the Fritts place. 
The openings are in an old field with no exposures of the granite nearby. 
The granite is probably slightly finer in texture than that of the Conrad 
place, but it is of the same color and contains about the same proportion 
of biotite. The rock quarried on this place is reported to have been used 
in the court-house building in Lexington. 

One mile north of Lexington on the Greensboro road and in front of 
the Leonard residence is a good section exposing the deca}*. to a depth of 
about 8 feet. The decay is light gray, slightly yellowish brown in 
color, in which the original minerals of the fresh granite are easy of 
determination. The feldspars are more or less kaolinized, chalky-white, 
and dull in appearance. Biotite flecks of a general brassy color' and 
brittle, indicating more or less leaching from chemical action, are abund- 
antly distributed through the mass. 



THE VARIETIES OF BUILDING STONES. 125 

THE SINK PLACE. 

Two miles south of Lexington and one-quarter of a mile east of the 
Lexington -Linwood road, directly on a small stream is an opening about 
100 feet long by 36 feet wide and 25 to 40 feet deep in a slightly schistose 
granite. The opening is practically of the same size as the flat-surface 
exposure of the granite in which it is made. 

The rock is a fine-grained, gray, biotite granite in which the schistose 
structure is apparent. Excepting the slightly schistose structure, it is 
similar in all respects to the granite described above on the Conrad place 
to the north of Lexington. Schistosity is probably more emphasized 
in the weathered rock in which a slight " augen " appearance is evident. 
The stone quarried from this opening is reported to have been used in 
Lexington and vicinity for various purposes. 

Microscopical Examination. — The microscope shows an aggregate of 
feldspar and quartz with biotite. The feldspar is principally orthoclase 
with much plagioclase and no microcline. Carlsbad twinning is com- 
mon. Peripheral shattering is very pronounced in fine-grained mosaics 
of quartz and feldspar completely surrounding the larger grains and 
filling the interstices of these minerals. Biotite has its principal distri- 
bution along and in the quartz-feldspar mosaic. Chlorite, epidote, and 
colorless mica are alteration products derived from the biotite. Addi- 
tional iron oxide, titanite, apatite, and zircon occur. 

About a quarter to a half mile south of the Sink opening and directly 
on the road a more gneissic phase of the same rock is exposed from grad- 
ing. It is very irregular in structure, usually fine-grained, somewhat 
thinly schistose with " augen " of white and pink feldspar. A pro- 
nounced tendency toward segregation into irregular wavy lines or bands 
in the biotite is exhibited. 

Microscopically, a thin section of the rock shows essentially the same 
mineral composition and structural features as that nearby in the Sink 
opening. Several scattered grains of microcline were noted. Crush- 
ing from dynamic metamorphism is greatly more emphasized in the thin 
section of this rock than that nearby at the Sink opening. Biotite is 
the chief accessory and shows the usual alteration products. 

The rock exposed. at this point can only be used in very rough grades 
of work. 

Porphyritic Granite. 

Beginning about 3| miles west of Lexington, on the Mocks- 
ville road, partially decayed, light gray, biotite granite of somewhat 
variable texture — fine to coarse grain — with slight porphyritic ten- 
10 



4 



* «. 



126 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

dency in places is exposed. Within a short distance westward the rock 
becomes typically porphyritic in texture and is continuously traced 
along the road by means of its decay into Davie County to Advance 
Station and beyond, a distance of 18 miles west of Lexington. 
No exposures of the entirely fresh rock were seen but the decay is typical, 
completely preserving the porphyritic texture of the fresh granite, and it 
affords equally as ready a means of tracing the area as the fresh rock. 
Variation in the decay is from light gray to yellowish red with the feld- 
spar phenocrysts still intact but much kaolinized. In the lighter col- 
ored decay the biotite has suffered but little alteration, but in the deeper 
colored areas much chemical alteration of this constituent is evident. 

The phenocrysts are usually of large size, flat tabular to irregular in 
outline, and they exhibit the usual Carlsbad twinning. Inclusions of 
biotite are quite conspicuous. 

The decay of this granite indicates a medium to coarse-textured, bio- 
tite, porphyritic granite, resembling in all respects the similar rock de- 
scribed in other parts of this report from G-aston, Iredell, Cabarrus, and 
Rowan counties. None of the fresh rock was procurable, hence further 
definite statements cannot be made. 

Dikes of Basic Igneous Rocks. 

Dike rocks of basic composition are common over many parts of 
Davidson County. In mineral types these rocks are essentially the same 
as for the adjoining counties, diabase, diorite, and more basic ferro- 
magnesian types are the most common. To the west of Lexington, dikes 
of diabase penetrating the granite have been noted at the following 
points along the Mocksville road : One and a quarter and 6-§ miles, 
respectively, west of Lexington; in the bed of a small stream, 7f miles 
west of Lexington; and 1-J miles west of Lexington along the same road 
a narrow belt of basic ferro-magnesian rocks occur. In the field the rock 
is coarse-textured, light to dark green in color, in which feldspar is not 
apparent megascopically. 

For several miles to the north of Lexington along the Greensboro road 
numerous greenstone schist dikes of variable width are exposed, striking 
in a general northwest direction. Similar ones are observed along the 
same road at many points between Lexington and Thomasville, and 
between Thomasville and High Point. About 5 miles south of High 
Point in the extreme northeast corner of Davidson County, the green- 
stone dikes are very abundant and are completely thinly schistose. From 
this point into High Point, Guilford County, both large and small dikes 
of diabase are frequent. 



THE VARIETIES OF BUILDING STONES. 127 

The much altered greenstone schist dikes apparently indicate a series 
of intersecting basic igneous rocks of a much earlier period of intrusion 
than the entirely massive unaltered diabase dikes of the same area. 

DAVIE COUNTY. 

The principal granite areas of Davie County are largely limited to the 
eastern half of the County, which represent the westward extension of 
similar rocks over the contiguous part of Davidson County, described 
above. Both even-granular and porphyritie granites of the biotite type 
are known. In addition to these is a single occurrence of a rather un- 
common and peculiar textured orbicular rock. The characterizing ac- 
cessory in this type of rock is amphibole without biotite. A complete 
description of the rock is given below. 

With the single exception of a few stones quarried on the Peter Hair- 
ston estate prior to the Civil War to supply certain local needs on the 
plantation, no granite has been quarried in Davie County. 

THE YADKIN RIVER GRANITE AREA. 

The Even-Granular Granite. 

THE HAIRSTON PLACE. 

To the northwest, west and southwest of the Peter Hairston residence 
in the middle eastern part of Davie County, near the Yadkin River and 
about 7 miles east of Advance Station, on the Charlotte-Winston 
branch of the Southern Railway, an extensive area of a fine-textured 
light gray biotite granite is traced from numerous exposures. About a 
quarter of a mile northwest of the Hairston residence, three or four 
small surface openings, near together, were made prior to the Civil 
War in flat-surface exposures of the granite. Only the surface stone 
was quarried and the openings indicate a rather advanced stage of decay 
in the rock. The rock quarried was used for various purposes in and 
about the Hairston residence. Although considerably weathered, it is 
safe to say that the fresh rock would prove to be a desirable granite for 
many grades of work. At the openings the granite is of uniform fine 
texture, gray in color and biotite-bearing. 

THE COOLEEMEE COTTON MILLS. 

In the extreme southern portion of Davie County and extending into 
the contiguous portion of Rowan County, along the South Yadkin River, 
13 miles northwest from Salisbury, numerous exposures of granite 
occur, especially at the Cooleemee Cotton Mills. The granite is exposed 



128 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

in the bed of the river under the cotton mills' dam and on the two sides 
of the stream. The clam was built of the stone qnarried from these 
exposures of the granite, and the rock has also been used to a limited 
extent for bridge piers. 

The rock is a medium coarse-textured granite, schistose in structure, 
and partially decayed. to the depth of the openings from which only 
surface raises have been made. The feldspars are in an advanced stage 
of kaolinization and the rock readily crumbles into a medium coarse- 
textured granitic sand when subjected to slight pressure. Three sets of 
joint-planes intersect the granite exposed near the dam, striking about 
1ST. 45° E., N". 45° W., and K-S. 

Microscopical Examination. — A thin section cut from a specimen of 
the rock collected under the dam at the Cooleemee mills showed under 
the microscope a biotite granite composed of both fine and coarse inter- 
locking aggregates of quartz and feldspar. Orthoclase, microcline, and 
striated plagioclase make up the feldspathic constituent. The biotite 
is much altered, principally to epidote. Irregular rounded areas of 
mi orographic intergrowths of quartz and feldspar are distributed through 
the section. The larger quartz and feldspar individuals are completely 
enveloped by a very fine mosaic of the same minerals derived from in- 
tense pressure-metamorphism. 

Porphyritic Granite. 

In the vicinity of the exposures of the even-granular granite described 
above the same rock grades into coarse textured porphyritic granite of 
the same mineral composition, which is described above as extending 
from 3| miles west of Lexington in Davidson County to and beyond 
Advance, a station on the Charlotte-Winston branch of the Southern 
Eailway. As previously stated/the area is readily traced by the residual 
decay of the granite which, in sections along the road, varies from a light 
gray to red, thickly studded with the large kaolinized feldspar phenocrysts, 
which occupy the exact positions in the decay as in the fresh rock. 

The phenocrysts vary from small and large irregularly rounded, to 
prevailingly flat-tabular, idiomorphic crystals invariably twinned on the 
Carlsbad law and containing abundant inclusions of the groundmass 
biotite. Over most of the area the surface is thickly strewn with the 
altered phenocrysts, which are usually broken into smaller pieces by 
splitting along the cleavage planes. 

The groundmass of the rock is a coarse-textured dark gray granite 
containing, as a rule, an increased percentage of biotite over the even- 
textured facies. 



THE VARIETIES OE BUILDING STONES. 129 

Orbicular Gabbro-Diorile. 32 

Ten miles west of Lexington and one mile west of Oaks Ferry on the 
Yadkin Kiver, are exposures of the orbicular diorite, which are less than 
a half mile east of north from the Hairston residence. These are in 
huge boulder form occupying a low indistinct ridge, which culminates 
in a peak or knoll about 30 feet in elevation above the surrounding 
plain. It is on this knoll that the typical orbicular rock is exposed in 
immense boulders covering probably as much as one or two acres of 
surface (see Fig. B, PI. XVII). 

Traced in a southwest direction from the knoll or peak is found com- 
plete evidence of the extension in that direction of the orbicular rock, in 
the residual decay, with occasional partially decayed fragments of the 
rock scattered over the surface. The decay is of a pronounced, nearly 
dark black color, with a decided greenish tone, imparted by the ferro- 
magnesian constituent of the fresh rock. Oxidation of the iron is no- 
where apparent. The zone of decay averages several hundred yards in 
width, as nearly as could be determined, and extends a half to three 
quarters of a mile southwest of the knoll. On each side of this narrow 
zone of decay sharp contacts between it and the porphyritic granite 
were observed in a number of places. The conditions, as closely as they 
could be traced and made out over the surface, leave practically no rea- 
sonable doubt that the orbicular rock occurs in the form of a typical dike 
penetrating the porphyritic granite and whose trend is northeast and 
southwest. It is practically parallel with and intersects the same rock 
as some half-dozen large dikes of massive and unaltered diabase in the 
vicinity, and is probably to be referred to the same age. 

Away from the knoll of exposed masses of the typical orbicular texture, 
the rock assumes a pronounced granitic texture or rather coarse texture 
and composed of the same minerals. There is a marked tendency in 
places toward the orbicular texture, with spheres very small and perhaps 
more nearly of the same size, less than one quarter of an inch in 
diameter. In other words, the rock presents two distinct and strongly 
contrasted phases, namely, orbicular and granitic. 

The color of the rock is dark with a greenish tone imparted by the dark 
green bisilicate. Viewed in detail, it presents a pronounced mottled 
appearance made up of dark green nodules of hornblende set close to- 
gether and in many cases touching each other, with the inter-nodular 
areas filled with clear white, cleavable and highly lustrous feldspar. The 

82 Orbicular Gabbro-Diorite from Davie County, North Carolina, by Thomas L. Wat- 
son, Journal of Geology, 1904, Vol. XII, pp. 294-303. 



130 BUILDING AND OENAMENTAL STONES OF NOETH CAROLINA. 

nearly black green nodules strongly contrast with the intensely white 
feldspar. As a rule, the spheres are well rounded varying in size from 
an eighth of an inch to, in extreme cases, several inches in diameter. As 
is seen in Plate XVIII, the dark spheres of the hornblende make up the 
bulk of the rock. The spheres show a tendency more or less strongly 
toward a fibrous radiating structure from a common center outward and, 
megascopically, are composed entirely of the dark green hornblende. In 
a few cases a small fragment of white feldspar forms the center around 
which the dark silicate arranged itself. Also quartz and p}^rite have 
both been observed as the nucleus about which the spheres of the dark 
green mineral were formed. 

The structure of the spheres in the Carolina rock is markedly different 
from that of such bodies usually observed in orbicular rocks described 
from Europe and the United States. In these a more or less pro- 
nounced concentric structure is observed in the minerals composing the 
spheres, some of the layers of which show in part at least the radiate 
fibrous arrangement. Still a second difference is in the composition of 
the spheres. As a rule, the spheres of orbicular granite and diorite 
hitherto described are composed of several minerals, generally the prin- 
cipal constituents of the groundmass, with, in many cases, additional 
minerals not present to any appreciable extent in the groundmass. Also, 
difference in color is observed from the center to the margin of the 
spheres, dependent upon the predominant mineral in any given portion 
of the sphere. In the Carolina rock a tendency toward radiate rather 
than concentric structure is indicated; composed of only one mineral, and 
of a single uniform color throughout. 

In the feldspar areas there are many large laths of the dark bisilicate 
of idiomorphic tendency, penetrating the feldspar without respect to 
orientation. A quarry is being opened up in this rock by the Consoli- 
dated Granite Co. of Winston-Salem, N". C. 

Microscopical Character of the Rock.^Six thin sections were prepared 
from selected chips of the rock for microscopical study. Five of the 
sections were cut from the nodules and one from a representative frag- 
ment of the interstitial filling or matrix. The character of the sections 
was such that only slight evidence was afforded of the structure of the 
nodules microscopically, but the radial arrangement of the minerals com- 
posing the nodules about a common center is entirely clear in hand 
specimens of the rock, as indicated in the megascopic description above. 

Diallage, green hornblende, basic plagioclase, microcline, quartz, 
titanite, muscovite, calcite, zoisite, magnetite, and an occasional zircon 
are the principal minerals of the rock. Essentially the same minerals 
are observed, as a rule, in both the matrix and the nodules, but in dif- 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XVII 




A. QUARRY NO, 



ROWAN GRANITE COMPANY, 4*4 MILES SOUTHEAST OF SALISBURY, SHOWING 
GRANITE DECAYED TO DEPTH OF 10 FEET. 



\ 




B. BOULDER OUTCROP OF ORBICULAR GABBRO-DIORITE, HAIRSTON FARM, DAVIE COUNTY, 10 MILES 
WEST OF LEXINGTON, DAVIDSON COUNTY. 



THE VARIETIES OE BUILDING STONES. 131 

ferent proportions; the matrix being composed very largely of feldspar, 
with very subordinate amount of most of the other minerals, and the 
nodules of the ferromagnesiaii minerals, with in many of them only the 
barest trace of the other minerals. Of the accessory minerals noted in the 
nodules, feldspar is usually in largest amount. 

The ferromagnesian minerals, diallage and hornblende, in varying 
amounts are present in all the sections. In many of them, probably a 
majorit}^, hornblende is subordinate in amount to diallage ; in others the 
two are in nearly equal proportion; and in still others hornblende is 
in slight excess. Diallage occurs in rather large irregular forms with- 
out crystal boundaries, exhibiting strong development of the ortho- 
pinacoidal cleavage. It is usually of faint greenish color and without 
sensible pleochroism. Minute microscopic interpositions are abundant, 
and it further incloses irregular grains and perfect idiomorphic crystals 
of hornblende. 

The hornblende is principally of the green uralitie kind, approxi- 
mating parallel columnar and fibrous forms, which usually show cleavage 
only in direction of elongation, but it entirely fails in some of the more 
irregular aggregates. Both the hornblende and diallage indicate some 
alteration (leaching) to nearly colorless forms. The angle of extinc- 
tion measured on many pieces of the hornblende varies from 13° to 20°. 
Pleochroism is confined chiefly to green tones, with the ray vibrating 
parallel to a appearing slightly yellow, and that vibrating parallel to 
h is occasionally tinged a faint brown. Compact hornblende in rhombic 
cross-sections, bounded by the prism and usually the pinacoid faces, and 
showing the intersecting prismatic cleavages, is distributed through the 
sections, with much of it inclosed by the diallage. 

Basic plagioclase is the predominant feldspar. Its substance is never 
fresh, but is largely altered to muscovite and calcite, and some zoisite 
which, with few exceptions, has completely destroyed the polysynthetic 
twinning lamellae. It occurs almost entirely as irregular, large grains 
without idiomorphic outline. Perfectly fresh microcline as irregular 
grains, and exhibiting the characteristic twinning structure, is present 
in every thin section studied. It sometimes occurs as inclusions of 
moderate-sized grains in the plagioclase. Abundant prisms of apatite, 
usually of fairly large size, are included in the feldspar. Some of these 
are in cross-sections which show perfect hexagonal shape; others are in 
longitudinal sections, and occasionally some of the apatite forms grains 
of irregular outline. 

Titanite is abundant in comparatively large idiomorphic crystals, 
yielding characteristic, sharply rhombic cross-sections. Some of it oc- 



132 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

curs in irregular grains without crystal outline. In thin section the 
color is pale to moderately deep brown, with slight absorption in the 
deeper-colored crystals. It is usually free from inclusions of other 
minerals. Cleavage is rather pronounced in much of it. 

Quartz is present in very subordinate amount in many of the sections, 
and it is probably largely, if not entirely, secondary. Muscovite and 
calcite are wholly secondary, and as such they present no noteworthy 
features. Magnetite and an occasional zircon complete the list of 
minerals. 

Summing up the results of the microscopic study, we find that the 
sections consist essentially of diallage, uralitic hornblende, and a basic 
plagioclase, showing, as a rule, but slight polysynthetic twinning, and 
usually altered to muscovite and calcite, or to zoisite and muscovite. 
The presence of perfectly fresh microcline in subordinate amount, a 
little quartz which is probably secondary, and a relatively large amount 
of accessory titanite and apatite is characteristic. Clearly the rock is 
a gabbro-diorite, although the presence in some of the sections of micro- 
cline and quartz is unusual. 

Several of the large boulders capping the knoll have been split and 
some of the stone has been worked up for various purposes. Prior to 
the Civil War, Mr. Peter Hairston, owner of the property, had a suf- 
ficient amount of the stone quarried to erect two very handsome gate- 
posts at the front approach to his premises and for steps to the house. 
The rock dresses well under the hammer and as indicated by specimens 
in the building-stones collection in the State Museum at Ealeigh, it is 
susceptible of high polish. No signs of decay are indicated in the stone 
used at the Hairston residence, although quarried many years ago. On 
a polished surface of the stone the effect is unique and beautiful, and 
the rock should prove to be of considerable value for ornamental and 
decorative purposes. 

On observing the weathered surfaces of the rock in the natural ex- 
posures, the feldspar is apparently the first mineral to go to pieces, as 
the spheres are picked up over the surface in a nearly fresh condition. 
The loose spheres picked up over the surface show little or no oxidation 
of the iron in the hornblende, but they contain the color of the nearly 
fresh rock. 

A polished column and sphere of this unique stone formed a part of 
the State exhibit at the Louisiana Purchase Exposition, held in St. Louis 
in 1904. 



1ST. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XVIII 




PHOTOGRAPH OF POLISHED SURFACE OF ORBICULAR GABBRO-DIORITE SHOWING THE SPHERES OF DARK 

GREEN HORNBLENDE. 



THE VARIETIES OF BUILDING STONES. 133 

Basic Igneous Intrusive Rocks. 

Excepting the dike of orbicular diorite described above and the area 
about Cooleemee cotton mills in the extreme southern part of the County 
on the South Yadkin Biver, only diabase dikes have been observed over 
those portions of Davie County studied during the past field season. 
These dikes are all similar in composition, completely massive and un- 
altered, except by superficial decay. They have been observed at the 
•following points and in every place they penetrate the granite. 

Three-quarters of a mile west of Oaks ferry on the Yadkin Kiver, 
two parallel dikes several hundred yards apart are exposed on the Mocks- 
ville road, trending N". 30° E., and 8 and 100 feet wide, respectively, 
penetrating the porphyritic granite. One-half mile south of the same 
road and 1J miles west of the ferry, a diabase dike with northeast trend 
and about 75 feet wide cuts the granite and passes directly through the 
north corner of the Hairston yard, where boulder exposures are observed. 
A second dike with the same trend and not less than 100 feet wide is ex- 
posed 300 yards north of the Hairston residence. Still a third dike of 
diabase having the same trend and width and intersecting the granite is 
exposed between the last dike and the Mocksville road. 

FORSYTH COUNTY. 

The principal areas of granite in Forsyth County are limited to the 
southeastern and eastern portions of the County, extending from near 
Winston southward and eastward into Guilford and Davidson counties. 
Outcrops of the fresh rock are not frequent but the granite is readily 
traced by its residual decay at the surface. Both porphyritic and even- 
granular biotite types of the granite are represented and the two tex- 
tures grade one into the other, representing different facies of the same 
mass of similar mineral composition. Over the other parts of the 
County the principal rocks are schists and gneisses whose origin is yet 
in doubt. 

No quarries have been regularly worked in the County but several 
small, openings have been made in somewhat widely separated outcrops, 
a few miles to the south and east of Winston, to supply a local demand 
for the stone in the above city. 

THE WINSTON GRANITE AREA. 

Porphyritic Granite. 

About 5 miles south of Winston and one-fourth of a mile east of the 
Lexington road, a surface exposure of a light gray porphyritic granite 



134 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

occurs on the Charles place. The exposure covers an area of 60 by 80 yards 
and has an average slope of about 14 degrees. By the stripping of the 
slight depth of decay, the dimensions of the area could be largely in- 
creased. A surface raise was made over a small part of the outcrop some 
years ago and the stone was worked into curbing and sills for use in 
Winston-Salem. 

The rock is a medium coarse-textured biotite porphyritic granite of 
light gray color. It is slightly schistose in places, and two sets of joint- 
planes penetrate the rock, striking N. 45° W., and N". 50° E. Most of 
the feldspar phenocrysts are roughly rounded and of more or less ir- 
regular outline, which with decrease in size grade into the same ground- 
mass constituent. Many of the phenocrysts, however, show idiomorphic, 
flat-tabular outlines, one-half inch in length by one-eighth inch across; 
they exhibit Carlsbad twinning and contain biotite inclusions. 

Microscopical Examination. — Under the microscope, a thin section of 
the rock indicates a biotite granite whose principal minerals are ortho- 
clase, mierocline, microperthitic intergrowths, quartz, and biotite. 
Plagioclase is only sparingly present. Secondary muscovite, chlorite, 
and epidote, with a slight sprinkling of certain minor accessories, com- 
plete the list of minerals. In the larger feldspar individuals, the micro- 
poikilitic texture is well developed, the included minerals consisting 
largely of the other feldspar species. Irregular areas of micrographic 
intergrowth of quartz and feldspar are quite freely distributed through 
the thin sections. The biotite is largely altered to chlorite, some epidote, 
and much colorless mica. 

About one-quarter of a mile west of the opening the granite is cut by 
a small diabase dike, exposed in the Lexington road. 

Outcrops of the partially decayed granite are observed along the road 
from near Winston south to the Charles place. The residual decay is 
typical and it affords a ready means of tracing the rock. Between 
Winston and the Charles opening the rock is an even-granular granite 
which grades southward into the porphyritic facies. 

About 5 miles southeast of Winston, on the Mssen place, are ex- 
posed some half dozen acres of flat-surface masses of a fine-textured, 
medium gray granite-gneiss. The area is crossed by a small stream 
which gives a gentle slope of the granite-gneiss exposures on either side, 
toward the stream. A single small opening was made near the stream 
in one of the exposures some years ago, and a few stones were quarried 
for local use in Winston-Salem. Several similar exposures of the same 
rock occur nearby. 

The rock is a biotite granite of schistose structure, and at the open- 



THE VARIETIES OF BUILDING STONES. 135 

ing contains some small grains and crystals of garnet distributed through 
it. Jointing is not conspicuously developed and at the opening only one 
set of planes could be positively determined, which indicated a strike 
of N". 80° W. 

Gneiss. 

About 3 miles east of Winston on the Maston place, and several 
hundred yards east of the Southern Railway near the Maston residence, 
a small opening was made some years ago in an outcrop of gneiss, and 
the rock was used in the construction of a bridge over one of the neigh- 
boring streams. The stone is unsuited for any purpose save that of 
rough work. 

The rock is an irregularly banded, dark biotite gneiss of variable com- 
position and texture. Some of tRe bands are highly feldspathic while 
in others this constituent apparently entirely fails. In places the rock 
assumes a typical schistose aspect of the biotite type ; in others the gneissic 
phase is strongly developed and made up of alternating quartz-feldspar 
bands with darker colored ones of biotite. The rock is garnetiferous 
in places. 

Microscopical Examination. — A thin section cut from a representative 
specimen of one of the gneiss bands showed, under the microscope, a 
rock of granitic composition, containing orthoclase, much plagioclase, 
quartz, and biotite as the principal constituents. Biotite is of the usual 
kind much altered to chlorite, and considerable muscovite derived from 
the alteration of the feldspar, occurs associated with more or less kaolin. 
The texture is rather coarse, and strain shadows and fractures in the 
larger quartz and feldspar individuals indicate the action of dynamic 
forces. 

From the opening on the Maston place west to Winston, 3 miles, 
the decay along the road and in the railroad cuts indicate the same rock 
penetrated by narrow dikes, and veins of granitic composition and of 
fine texture. 

Diabase Dikes. 

Dikes of massive diabase are rather frequent over the areas studied 
in Forsyth County. About one-quarter of a mile west of the Charles 
granite opening and crossing the Lexington road, 5 miles south of 
Winston, is a diabase dike penetrating the granite, less than 50 feet 
wide with an approximate north-south strike. One and a half miles 
east of Winston is a second dike of diabase about 25 feet wide and strik- 
ing a few degrees west of north, which is exposed on both sides of the 
road. 



136 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Microscopical Examination. — Microscopically, a thin section cut from 
a hand specimen of the last dike, shows the rock to be a typical olivine 
diabase, composed of long, very thin blades of plagioclase, with the inter- 
stices filled with small idiomorphic crystals of augite, magnetite and 
olivine. The ophitic structure is most characteristically developed. 

Within the northwest limits of Winston-Salem, in a cut along the 
Mocksville branch of the Southern Eailway, is an unaltered massive 
diabase dike 200 feet wide and striking N". 20° E., as nearly as could 
be determined. About three-quarters of a mile southwest of Bethania, 
a station on the Wilkesboro branch of the Southern Railway, and eight 
miles northwest of Winston-Salem, a very large diabase dike is exposed 
penetrating mica schist. The dike, where exposed, has a width of 200 
to 500 feet and trends JST. 20° E. At the point where examined, the dike 
apparently conforms to the schistosity of the enclosing schist and does 
not cut across it as in most cases. Results of tests of this rock for road 
material are given on page' 265. 

GUILFORD COUNTY. 

The principal granite areas of Guilford County are confined to the 
western, northern and central portions of the County. Indeed they are 
extensive over the entire west half of the County. With one exception, 
the granites are of even-granular texture and carry biotite as the chief 
characterizing accessory. The exception is that of a porphyritic granite 
occurring near Friendship in the middle western part of the County. 
Examination of the granite outcrops in all parts of the County indicates 
that they have more or less of the schistose structure developed in them, 
with some additional evidence of crushing and mashing from pressure- 
metamorphism. 

Regular quarries have nowhere been worked in the County but open- 
ings have been made in many places to obtain stone of a certain grade 
for local use. The granites of Guilford County are best treated sepa- 
rately under the following five areas : The Brown Summit Area ; The 
Summerneld Area ; The Friendship Area ; The Jamestown Area ; and 
the Greensboro Area. 

THE BROWN SUMMIT GRANITE AREA. 

One and a half miles southeast of Brown Summit, a station on the 
main line of the Southern Railway, and 10^ miles slightly east of north 
from Greensboro, on the Walker Place, are fiat surface expos- 
ures of a light gray schistose granite, extending over several acres of 



THE VARIETIES OF BUILDING STONES. 137 

surface. Westward in a direct line the railroad is reached at a distance 
not exceeding f of a mile. Some of the granite was reported to have been 
first quarried prior to the Civil War for use on the Walker place as steps, 
blocks, etc. It was more extensively worked later for stone to be used on 
the streets and in some of the buildings in Greensboro, and to some extent 
in bridge construction. 

The rock is a biotite granite, schistose in structure, and contains much 
muscovite in places. It is quite variable in texture and color and is 
penetrated by very many veins and dikes of pegmatite, composed largely 
of feldspar and quartz with a sprinkling of biotite. These intersect 
the rock in nearly all directions, but probably a majority of them con- 
form to a N". 60° E. direction, and a second direction at approximately 
right angles to this one. The veins are sometimes observed cutting 
across each other with a displacement of several inches. The principal 
jointing strikes N". 60° E., and the surfaces of the joints are more or 
less completely slickensided. On account of the shearing and schistose 
structure and the rather numerous veins, the use of the granite is limited 
to the lower grades of work. 

Microscopical Examination. — Microscopically, a thin section of the 
rock from this place shows a biotite granite of fine texture, composed 
of an aggregate of quartz, microcline and orthoclase with very scant 
plagioclase, and some biotite altered in part to chlorite. Effects of 
pressure-metamorphism are pronounced through the section. A few 
scattered grains of black magnetite occur. 

Between this area of schistose granite on the Walker Place and Gray's 
Mill, one mile south, the country rock is a basic greenstone much crushed 
and mashed and closely jointed. It is otherwise altered in its mineral 
constituents which makes it uncertain as to what it was originally. 

Nine miles north of Greensboro on the Eeidsville road, flat-surface 
outcrops of a variable biotite gneiss are exposed for some distance along 
and on both sides of Eogers Branch. The rock is a dark hornblende- 
biotite gneiss of irregular schistosity, and variable in texture and com- 
position. It contains a large proportion of the dark silicates and its 
variable character makes it unsuited for any but rough grades of work. 
It is penetrated in many places, at close intervals, by very thinly schis- 
tose greenish black basic rock in the form of dikes not exceeding 18 inches 
in width and striking in a general northeast direction. 

Microscopical Examination. — A thin section of the schistose rock in- 
dicates under the microscope a hornblende-biotite gneiss in which horn- 
blende is more abundant than the biotite. The hornblende shows some 
leaching and considerable alteration to the " reedy " form. Biotite dis- 



138 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

plays its usual color and absorption and is closely associated with the 
hornblende. The quartz and feldspar, the former greatly in excess, 
form very fine granular interlocking mosaics distributed along more or 
less parallel lines between la}^ers of the dark silicates, emphasizing the 
gneissic structure. 

The rock northward between this point and Gray's Mill on Eeedy 
Fork, and along the Keidsville road, is a variable mica schist, largely 
sericitic, as indicated by the residual decay. Beginning 5^ miles north of 
Greensboro and extending northward 3-J to 4 miles along the Eeidsville 
road to the exposures of gneiss described above on Eogers creek, the 
country rock is a variable mica schist ranging from sericitic to quartzitic 
in composition. 

THE SUMMERFIELD GRANITE AREA. 

Summerfield is a station on the Sanford and Mt. Airy branch of the 
Southern Kail way, and is 12 miles northwest of Greensboro. About 
6 miles west of Greensboro on the Battle Ground road, a medium fine 
textured biotite granite outcrops on both sides of the road. The rock has 
been opened both on the north and the south sides of the road to obtain 
macadam for the road. The granite is continuous westward from this 
point to and beyond Summerfield, a distance of 6 miles. It is porphyr- 
itic in places but the rock over the greater portion of the area is an 
even-granular granite, the two textures representing different phases of 
the same granite mass. The granite is penetrated by a number of 
diabase dikes to the east of Summerfield, along the Greensboro road. 

. . THE HOSKINS PLACE. 

About a quarter of a mile south of Summerfield, on the Hoskins place, 
large boulder outcrops of a fine textured, schistose, biotite granite are 
exposed over several acres of surface. The granite appears entirely 
massive in places but it exhibits a pronounced schistose structure in 
others. In the schistose portions of the rock the banding is irregular 
and, in places, is contorted and crumpled. Two sets of joints intersect 
the rock striking K 10° E., and N". 70° E. 

A small opening has been made in one of the exposures and some of 
the stone was quarried for local use. The rock is not suited for the 
better grades of work in which granite is used. 

Microscopical Examination. — Under the microscope, a thin section of 
the rock shows a fine-textured biotite granite of closely interknit feld- 
spars and quartz in which lie small, irregular shreds of biotite largely 



THE VARIETIES OF BUILDING STONES. 139 

altered to chlorite. Single plagioclase individuals are absent and the 
feldspar content is composed of potash varieties and microperthitic in- 
tergrowths. No injurious minerals occur. 

THE GAMBLE PLACE. 

One mile southwest of Summerfield, on the Gamble place, a flat dom- 
ing granite mass is exposed along a tiny stream, from which some stone 
has been quarried. Blocks and curbing were quarried for use on the 
streets of Greensboro. The rock is well adapted for this purpose, but 
as shown in the description which follows it is not a desirable granite 
for the better classes of work in which granite is used. The opening 
is approximately 50 yards square, with a quarry-face of about 12 feet in 
depth. 

The rock is a biotite granite of variable color, texture and structure. 
Variation is from medium fine even-grained to medium coarse-grained 
porphyritic granite; from massive to schistose in structure; and from 
light to medium dark gray in color. The schistose structure is rather 
marked in places and .very many dark irregular segregation areas of 
biotite are contained in the rock. 

Microscopical Examination. — Thin sections cut from specimens of 
this rock show microscopically a medium fine-grained biotite granite 
composed of an aggregate of complexly interlocking feldspar and quartz 
in which lie the irregular shreds of biotite altered in part to chlorite 
and a colorless mica. Peripheral shattering is indicated in one of the 
sections. Potash feldspars with microperthitic intergrowths and very 
sparse plagioclase compose the feldspathic constituent. Both micro- 
graphic intergrowths of feldspar and quartz and micropoikilitic structure 
in some of the feldspar are well developed. No injurious minerals were 
noted in any of the thin sections. 

So far as exposed, the porphyritic phase of the granite predominates 
over the even-granular texture. The feldspar phenocrysts are both ir- 
regular roughly rounded in outline and flat-tabular, one-half to 2 
inches in length by one-half inch wide and frequently twinned on the 
Carlsbad law. 

About 3 miles northeast of Summerfield, in the vicinity of Plat 
Rock church and near the railroad, some blocks for street purposes are 
reported to have been quarried in an outcrop of granite similar to that 
on the Gamble place. The writer was unable to visit this opening. 

The granite is continuously traced by its residual decay in a north- 
south direction between Summerfield and Friendship, a distance of 10 
miles. It is typically porphyritic in places, and grades into the even- 



140 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

granular granite of the same mineral composition. Dikes of diabase 
intersect the granite at several points along the road between Summer- 
field and Friendship. About half-way between the two stations and 
about three-quarters of a mile north and northwest of Pleasant Eidge 
church, the even-textured biotite granite has been opened to a very slight 
extent in several places. 

THE FRIENDSHIP GRANITE AREA. 

Friendship is a station on the Wilkesboro and Winston- Salem division 
of the Southern Eailway and is 10 miles west of Greensboro. 

THE MCGRADY QUARRY. 

Three miles "N. 25° E. from Friendship, two openings about half a 
mile apart in an east-west direction have been made in outcrops of 
biotite granite, and some of the stone has been quarried. The openings 
are reported to have been made many years ago to obtain stone for 
building culverts along the railroad. The openings are small and re- 
present only surface stripping, worked to a depth not exceeding 8 or 
10 feet. 

The rock is a porphyritic biotite granite of variable texture and color, 
and of rather inferior quality. The amount of biotite is rather large 
in places and perhaps a dark gray color prevails. 

Microscopical Examination. — A thin section of the rock collected 
from the east opening indicates, under the microscope, a biotite granite 
composed of the following principal materials : quartz, orthoclase, much 
plagioclase, microperthitic intergrowths, biotite, titanite, zircon, apatite, 
chlorite, and muscovite. Biotite is rather abundant, associated with the 
titanite and containing large inclusions of prismatic zircon. Micro- 
graphic and micropoikilitic structures are developed. 

Outcrops of the granite are reported between Friendship and Oak 
Ridge, and in the vicinity of the latter, 5 miles northwest of Friend- 
ship, and within a few miles of the Forsyth County line. Likewise the 
granite is traced by its decay for some distance along the road from 
Friendship eastward toward Greensboro. 

THE JAMESTOWN GRANITE AREA. 

One-half mile southeast of Jamestown on Bull Run, an opening was 
made some years ago in a ledge exposure of granite-porphyry for stone 
to build a culvert over Bull Run at the railroad crossing. A few hundred 
paces further down the stream a second smaller opening has been made 
in the same rock. 



THE VARIETIES OF BUILDING STONES. 141 

The rock is a fine-grained, dark gray, thinly schistose granite-por- 
phyry, composed of bluish opalescent quartz, white opaque feldspar and 
biotite. The mass is penetrated at close intervals by two sets of joints 
which strike N". 40° W., and N". 20° E. It cannot be used for general 
building purposes because of the close jointing not admitting of dimen- 
sion stone being quarried; otherwise it is an excellent rock, possessing 
great hardness and toughness. 

Microscopical Examination. — A thin section of the rock from this 
opening, examined under the microscope, indicated a distinct granite- 
porphyry. The section shows an exceedingly fine-grained groundmass 
of quartz and feldspar with some biotite largely altered to chlorite, much 
epidote, and a colorless mica, in which are embedded porphyritic crystals 
of plagioclase (oligoclase) and orthoclase feldspars, and one or two of 
quartz. The phenocrysts show no tendency toward orientation and those 
of feldspar are filled with dust-like inclusions and are otherwise much 
altered, principally into muscovite shreds. Some magnetite and leu- 
coxene very sparingly occur. 

A few hundred feet north of the opening the granite-mass is pene- 
trated by a diabase dike which strikes N". 40° -50° W. Boulders of 
the dike are exposed over the surface on both sides of the mill road, a 
quarter of a mile west of the opening. 

OAKDALE COTTON MILL. 

One mile southeast of Jamestown at the Oakdale cotton mills, on 
Deep Eiver, large boulder and ledge exposures of a very similar rock 
to that described above on Bull Eun are observed. Much blasting was 
necessary in the construction of the dam across the river at the cotton 
mills, affording excellent exposures of the granite. The granite area 
is a large one and wherever exposures were observed the rock was more 
or less schistose in structure. Dark areas of segregated biotite of ir- 
regular outline and variable size are frequent in the rock. 

The rock is of medium texture, somewhat resembling that exposed 
on Bull Eun except that it is coarser in texture, more schistose in struc- 
ture, and the quartz is not of the blue opalescent kind. Where exposed 
at the dam across Deep Eiver, 4 parallel dikes of what is apparently 
diabase penetrate the granite, from 1 to 15 feet in width and con- 
forming to a N". 20° E. strike. The contacts between the dikes and the 
enclosing granite are perfectly sharp where observed in exposures of the 
fresh rock. The dike rock is very fine grained and more or less schis- 
tose in structure. Eesults of tests of these rocks for road material are 
given on page 265. 
11. 



142 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Microscopical Examination. — A thin section cut from a specimen of 
the rock collected at the dam of the cotton mills on Deep River, showed, 
under the microscope, a biotite granite of medium texture. The principal 
mineral composition of the rock is potash and plagioclase feldspars, 
quartz and biotite, with some peripheral shattering from dynamic forces 
indicated. . Orthoclase is the predominant feldspar associated with much 
plagioclase and very little microcline. Both the feldspar and the biotite 
show more or less alteration of the usual kind. A few scattered grains 
of magnetite occur and slight development of the micropoikilitic struc- 
ture in some of the feldspar is noted. 

THE MODLIN QUARRY. 

Four miles northeast of High Point and 1J miles southeast of 
Jamestown on the H. C. Modlin place, a rather extensive opening 
was made some years ago in a fine to medium-grained granite to 
obtain stone for building bridges and culverts along the Southern Rail- 
way, which passes within a short distance of the Modlin property. The 
opening was worked to a considerable depth and a large amount of the 
stone is reported to have been quarried. 

The rock is a fine to medium grained biotite granite of medium to 
dark gray color, and fairly uniform in both color and texture. It is a 
desirable granite for many purposes, and so far as an examination re- 
veals, it contains no injurious minerals. Numerous outcrops of granite 
are exposed over the Modlin place, but as yet only the single opening 
has been made. 

Microscopical Examination. — A thin section of the rock from the 
quarry opening on the Modlin place showed, microscopically, a biotite 
granite of medium fine texture. The principal minerals are, much 
plagioclase and orthoclase feldspars, quartz, and biotite, with no iden- 
tified microcline. The usual accessories common in granite occur with 
no injurious ones noted. Effects of dynamo-metamorphism manifested 
in fractures, strain shadows and some peripheral shattering are rather 
marked in the thin section. 

THE GREENSBORO GRANITE AREA. 
THE CITY QUARRY. 

This quarry is located about 1| miles north of the court-house in 
Greensboro. The opening, worked in August 1903, was about 350 
by 100 feet and 6 to 8 feet deep. The rock was being quarried 
at the time for macadam and the method used was blasting with 



THE VARIETIES OF BUILDING STONES. 143 

dynamite, which shattered the stone so much as to destroy the 
value of the rock in the opening for any other purpose. A rock crusher 
was being operated at the quarry for sizing and grading the stone; 
Results of tests of this rock for road material are given on page 265. 

The rock is a medium coarse-grained biotite granite, massive in struc- 
ture and of medium gray color. It is quite uniform in both color and 
texture and it is of pleasing appearance but dimension stone cannot be 
quarried because of the close jointing. The strike of the joints is ST. 
20° E., N". 50° E., and 1ST. 20° W. Slickensided surfaces are well devel- 
oped along the jointing. The rock displays the effects of crushing and 
fracturing from pressure metamorphism, and it is penetrated by a num- 
ber of dark greenish black amphibolite dikes. The dikes vary from 
a few inches to 18 inches in width and are parallel, cutting the granite 
at irregular intervals and conforming to a 1ST. 20° E. strike, which is coin- 
cident with the jointing in that direction. 

Microscopical Examination. — A thin section prepared from a specimen 
of the rock collected from the City quarry shows, microscopically, a 
biotite granite of medium texture. Nearly equal striated plagioclase 
and orthoclase with very little microcline, quartz and biotite make up 
the essential minerals in the section. The feldspars are all more or less 
completely clouded from alteration. Biotite is largely altered to chlorite 
and epidote, and a very slight sprinkling of magnetite grains occurs. 
No injurious minerals were noted in the thin section. 

THE COUNTY QUARRY. 

The County quarry is located near the ball grounds in the northeast 
limits of the city of Greensboro on the Cone property. The rock is a 
variable textured diorite penetrated by numerous dikes of altered 
diabase. The rock has been much crushed from pressure metamorphism 
and both it and the dikes are closely jointed, the surfaces of some of 
which are slickensided. The joint-planes strike N.-S., E.-W., and N. 
40° W. The dikes vary in width from a few inches to nearly 50 feet 
with small stringers penetrating outward from the dikes into the diorite. 
Results of tests of this rock for road material are given on page 265. 

Variation in the diorite is from a coarse nearly black rock, in which 
the hornblende is in large, partially idiomorphic crystals, to one of a 
medium-fine even grain. The feldspar content varies considerably from 
place to place, imparting a lighter color to the rock where it is present 
in maximum amount. 

Microscopical Examination. — A thin section of the rock from the 
County quarry shows under the microscope a typical diorite, composed 



144 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

of much large platy hornblende of greenish blue color with slight pleo- 
chroism accompanied by the separation of much black magnetite grains 
as inclusions, and short, stout laths of striated plagioclase. The horn- 
blende is principally an altered or "reedy" form. 

A thin section prepared from a specimen of the rock penetrating the 
diorite in the form of dikes shows, microscopically, a uralitic diabase, 
of rather fine grain. The original augite is almost entirely altered to 
the " reedy " form of hornblende. Long, slender laths of plagioclase 
indicate more or less tracing of the diabase structure. Magnetite is 
quite freely distributed through the section. 

The dimensions of the opening are approximately 300 by 150 feet 
and worked to a depth not exceeding 12 feet. A rock crusher was 
operated at the quarry and the stone was used for macadam purposes. 
Four to 5 feet of a deep reel, and stiff residual clay derived from the 
decay of the diorite covers the fresh rock in places in the quarry sec- 
tions shown, which it is necessary to strip before quarrying. 

Along the Eeidsville road, 3f to 5J miles northeast of Greens- 
boro, the rock is of decided dioritic composition and appearance 
and is closely jointed. It affords some evidence of having been 
mashed and squeezed from pressure metamorphism and is pene- 
trated by innumerable veins and dikes of granitic composition. 
A thin section of as fresh a specimen of the rock as it was possible 
to obtain indicated under the microscope such extreme alteration that 
very little satisfactory evidence as to its petrography could be made out. 
So far as it was possible to interpret it, there seemed to be not much 
question of referring it to a diorite. 

About 5-| miles northeast of Greensboro along the same road are ex- 
posures of a partially decayed fine-textured, light gray biotite granite, 
displaying pronounced effects of pressure metamorphism and close joint- 
ing. For this reason, the rock is entirely unsuited for any purpose, ex- 
cept as road material and ballast. 

INTRUSIVE DIKE ROCKS OF BASIC COMPOSITION. 

Basic intrusive rocks are somewhat numerous over all parts of Guil- 
ford County. The principal types include diabase and diorite, and their 
altered products, greenstone and amphibolite. Both massive and schis- 
tose structures are represented in the rocks and on this basis not all of 
the dikes belong to the same period of intrusion ; but several periods 
are represented. In all cases the rocks are typical of the kinds rep- 
resented and megascopically they do not display any unusual noteworthy 
features. 



THE VARIETIES OF BUILDING STONES. 145 

Diabase Dikes. 

Diabase forms perhaps the most frequent type of basic igneous rock 
of Guilford County. The most important dikes noted are as follows: 
One mile west of Greensboro near the cemetery on the Battle Ground 
road a dike of diabase 100 feet wide and striking in a general northeast 
direction penetrates the granite 33 ; City quarry, 1-| miles north of Greens- 
boro, a parallel series of diabase dikes striking N". 20° E., and varying 
from a few inches to 18 inches wide; 2-| miles southwest of Greensboro 
on the Spring Garden road is a narrow dike striking approximately north- 
west; 3^ miles northeast of Greensboro is a dike 15 feet wide striking 
north and south, exposed along the Reidsville road. 

About 10-J miles east of north from Greensboro and three-quarters of a 
mile northeast of the Hardy residence, where the Doggett mill road 
crosses a small stream is a dike 200 feet wide striking north 
and south. Three miles east of Greensboro on the Eankins saw-mill 
road is a dike about 25 feet wide and striking in a northwest direction. 
Between the Guilford Battle Ground and Summerfield, 12 miles north- 
east of Greensboro, a number of small dikes penetrate the granite 
and are exposed along the road, for several miles southeast of Hamburg's 
mill. At the mill 3 miles southeast of Summerfield a large dike is 
exposed with a probable northeast strike. Between Friendship and 
Summerfield, a north-south distance of 10 miles, the granite is pene- 
trated at a number of points along the road by diabase dikes. 

On the Greensboro road, 3 miles northeast of High Point, a dike 
25 feet wide and striking northeast is exposed. Between Deep River 
and Jamestown is a second dike of the same width and strike. On the 
east side of the railroad at Jamestown is a third dike with the same 
strike ; width not determined. At the quarry on Bull Run, one-half mile 
southeast of Jamestown, is a large dike striking N". 40° -50° W. At 
the dam across Deep River, 1 mile southeast of Jamestown, the 
granite at the Oakdale cotton mill is intersected by a series of paral- 
lel dikes, 33 varying from 1 to 15 feet in width and striking 1ST. 20° E. To 
the south of High Point along the Lexington road the rocks are pene- 
trated by numerous dikes, the largest one of which is 600 feet wide. 
The diabase dikes in this locality have a general approximate north- 
west strike. 

Diorite. 

To the north of Greensboro, diorite forms one of the most important 
rock types, where extensive areas of it are developed in places. The rock 

83 Results of tests of this rock for road material are given on page 265. 



146 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

is best exposed at the County quarry, within the northeast limits of the 
city of Greensboro. One mile west of Greensboro and near the cemetery 
on the Battle Ground road, a diorite dike 18 feet wide and striking 
northeast penetrates granite within 100 feet of a large diabase dike 
having the same strike. Eesults of tests of this rock are given on page 
265. Microscopic study of a thin section of this rock indicates a typical 
diorite. 

Greenstone Dikes. 

These are altered basic igneous rocks derived probably from both 
diabase and diorite, and they are usually more or less schistose in struc- 
ture. They are regarded as being older in age than the dikes of massive 
diabase and diorite described above. The best exposures of these rocks 
are seen at the following places : Along the Battle Ground road between 
Greensboro and the cemetery. They are partially decayed and schistose 
and in width vary from 2 to 4 feet. On the Greensboro road, at Deep 
Eiver bridge, one-quarter of a mile west of Jamestown, is a completely 
schistose dike more than 100 feet wide and striking northeast. For 
several miles east of Greensboro along the Ashboro road very many dikes 
of greenstone schist are exposed penetrating the granite decay. Seven 
miles northeast of Greensboro at Bankings saw-mill large boulders of 
greenstone outcrop on both .sides of the stream. The rock is porphyritic 
in places and projecting stringers or veinlets penetrate the granite rock 
on the southwest side of the stream along the road. Still another area 
is mentioned above between the Walker place and Grays mills, 9 to 10 
miles east of north from Greensboro along the Eeidsville road. 

Amphibolite. 

Along the Eeidsville road immediately on the south side of Eogers 
Branch, hornblende-biotite gneiss is intersected by a number of thinly 
schistose dikes composed largely of hornblende, the width of which do 
not exceed 18 inches, and which have a northeast strike. 

Gabbro. 

Along the Ashboro road, near Sharps school-house, 2^ miles south- 
east of Greensboro, is a dike of coarsely crystalline basic eruptive rock, 
probably not less than 1,000 feet wide and having a general northeast 
direction. Large boulder outcrops of the rock are exposed for a quarter 
of a mile southeast of the school-house. The boulders have been quarried 
to a slight extent in several places for macadam. 



THE VARIETIES OF BUILDING STONES. 147 

Microscopical Examination. — Microscopically, a thin section of the 
rock showed much colored augite with faint pleoehroism filled with 
grains of magnetite, hornblende, with the feldspar areas completely 
altered to a fine mosaic of different minerals. Results of tests of this 
rock for road material are given on page 265. 

ALAMANCE COUNTY. 

THE BURLINGTON GRANITE AREA. 

Granites of irregular color and texture are found in the vicinity of 
Burlington, the county-seat, principally to the north, east, and southeast 
of the town. The outcrops are very few and small, and the rock is 
identified and traced mainly by its residual decay, which covers the fresh 
rock to some depth and consists usually of a light gray, sometimes red, 
siliceous to clayey soil. The rock is schistose in places, always biotite- 
bearing and of little value except in the ordinary lower grades of work. 
The color varies from nearly white, in which little or no biotite occurs, 
to medium and dark gray containing a goodly proportion of biotite. In 
texture, variation is from moderately coarse to fine-grained. 

A number of very small openings have been made in places to obtain 
stone for purely local purposes. About 4 miles north of Burlington, 
small quantities of the granite have been quarried from time to time 
for window and door sills in factories of that vicinity. Again, to the east 
of Burlington, 1-J miles just off and to the north of the Haw River road, 
a small opening has been made in a schistose granite of variable struc- 
ture, texture and color, for use as macadam. Near the southeast limits 
of the town a small amount of stone was quarried from a surface stripping 
of a small exposure of the granite. The rock at this point also lacks 
uniformity in color and texture. 

Microscopical Examination. — Microscopic study of a thin section of 
the rock collected from the opening near the southeast limits of Burling- 
ton indicated a biotite granite, composed of a medium coarse aggregate 
of quartz and feldspar, in which lie altered shreds of biotite. Microcline 
entirely fails and striated plagioclase equals in amount orthoclase, both 
of which are largely altered to epidote and some other less important 
accessories. The quartz occupies distinct areas through the section. No 
injurious minerals are indicated under the microscope. 

THE HALL PLACE. 

About 3 miles north of Burlington and a quarter of a mile north- 
west of Glencoe, a small quantity of stone has been quarried from an 
exposure of granite on the Hall place. The rock is a biotite granite of 



148 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

rather irregular texture and color, mostly medium-grained and 
gray in color. The exposure is a small one and the stone, so far as 
developments indicated, is not of very desirable quality, though it can 
be used to advantage for many purposes. 

Microscopical Examination. — Microscopically, the rock is a medium- 
grained biotite granite, composed largely of orthoclase with a small 
quantity of both plagioclase and microcline, quartz and biotite. Biotite 
was rather sparingly distributed through the section and several grains 
of pyrite were noted. The micropoikilitic structure was well developed 
in some of the larger feldspar individuals. 

THE ALTAMAHA GRANITE AREA. 

Altamaha is the name given to an area of syenite-porphyry exposed 
along Haw Eiver and its tributaries, especially Eeedy Fork, at the 
Altamaha and the Ossipee cotton mills, about 7-J miles northeast of 
Burlington. The nearest railroad point is Elon College, a station on the 
Greensboro-Groldsboro branch of the Southern Eailway, distant about 
5 miles south of the area. 

The two mills, Altamaha and Ossipee, are about one mile apart in an 
approximate north-south direction. The first exposure of the rock is 
observed at the bridge along the river on the opposite or south side from 
Altamaha, and is traced from this point southward to the Ossipee mills, 
where large outcrops occur on both sides of the stream. The exposures 
are in the nature of ledge and boulder outcrops along the streams, and 
as boulder and flat surface masses between the streams. On the opposite 
or north side of Eeedy Fork from the Ossipee mills extensive ledge and 
boulder exposures of the stone occur from which much of the rock was 
quarried about 5 years ago, and used principally for constructing the 
dams across the streams at the mills. The strike of the joint-planes at 
this point is N". 10° E., and K 60°-70° W. The rock is further pene- 
trated by some veins of pegmatite, but not sufficiently abundant nor of 
large enough size to in any way interfere with the quarrying of desirable 
dimension stone. In places, pyrite in large and small irregular masses 
and grains is quite freely distributed through the rock. Blocks of the 
stone of any dimension are obtainable from these exposures. A few 
stones have been obtained recently from a very small opening made in 
an exposure of the rock directly in front of the new brick church be- 
tween the two mills, but nearest Altamaha. 

Megascopically, the rock is a compact, exceedingly hard, fine-grained, 
dark gray syenite-porphyry. The feldspar phenocrysts are not large and 



THE VARIETIES OF BUILDING STONES. 149 

are accordingly not conspicuously developed in the rock. To the north 
of the Ossipee mills, in front of the church and at the bridge at 
Altamaha, the texture of the rock is even-granular or non-porphyritic. 
Both the color and the texture of the rock are quite uniform. The 
rock is quite lively and pleasing in appearance and is a very desirable 
stone for general building and other purposes. It is very hard and tough 
and would probably increase the cost of quarrying somewhat above the 
general average for true granites. 

Microscopical Examination. — Microscopically, a thin section of the 
rock exposed in the openings made on the opposite side of the stream 
from the Ossipee mills showed a fine-grained biotite syenite-porphyry. 
Named in . order of their abundance the groundmass minerals are 
orthoclase, oligoclase, biotite, muscovite, epidote, magnetite, leucoxene, 
pyrite, and some crypto-crystalline quartz. Idiomorphic striated plagio- 
clase (oligoclase) and some orthoclase, with fewer biotite phenocrysts 
are imbedded in the groundmass. 

A similar section cut from the rock exposed at the bridge opposite 
Altamaha, indicated microscopically the same rock, but of non-porphyr- 
itic texture and much altered. The amount of biotite and short, stout 
laths of a striated feldspar is increased over that at the Ossipee mills. 
The minerals are, named in order of their abundance, orthoclase, biotite, 
oligoclase, epidote, muscovite, magnetite, and leucoxene. 

BASIC IGNEOUS ROCKS. 

Eocks of basic igneous type are very abundantly distributed over por- 
tions of Alamance County. These may be divided conveniently into 
two classes, namely, greenstones which are more or less thinly schistose, 
altered volcanics extensively exposed over the eastern half of the County, 
and especially well exposed along Haw Eiver at the Haw Eiver station 
to the east of Burlington about 4 miles; and dikes comprising prin- 
cipally diabase, diorite and gabbroitic forms. The dikes are numerously 
exposed along the principal roads to the south and the east of Burling- 
ton, and again between Burlington and Altamaha. They are especially 
well developed in the vicinity of Grlencoe and further north in the direc- 
tion of the Altamaha granite area. 

About one mile northeast of Haw Eiver station, and a quarter of a 
mile north of the Macadam road, a recent opening has been made in a 
flat-surface exposure of the greenstone. The rock was quarried for use 
in macadamizing the roads. It is very tough, much crushed and mashed 
from dynamic forces, closely jointed and more or less schistose in struc- 



150 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

ture. A rock crusher and classifier is located at the opening for crush- 
ing, grading and sizing the stone for macadam. Eesults of tests of this 
rock for road material are given on page 265. 

RESUME OF THE GRANITES OF THE CAROLINA IGNEOUS BELT. 
(THE MAIN GRANITE BELT.) 

Briefly summarizing the important points developed in the descrip- 
tions of the individual granite areas of the Main Granite Belt of the 
State, it is shown first, that granite is one of the principal and most wide 
spread rocks found within the limits of the belt. Extensive areas of 
granite are exposed more or less in each of the 10 counties included 
within the belt and, in each county some stone has been quarried from 
time to time, usually to satisfy only an immediate local demand. Not- 
withstanding the wide distribution of granite over the belt, only one 
county within the belt has undertaken systematic quarrying, namely, 
Rowan. In this county quarrying has been confined to the Dunns 
Mountain granite ridge and its southwestward extension to the east 
and the south of Salisbury, where the earliest quarrying antedates many- 
years the Civil War. 

Texturally, two distinct phases of the granite are developed, an even- 
granular or normal, and a porphyritic granite, both of which have wide 
distribution within the limits of this belt. With only one exception 
the two textures represent different phases of the same rock mass, the 
porphyritic texture grading into the even-granular. The single excep- 
tion is in the Mooresville granite area of Iredell County, where the field 
evidence conclusively indicates that the even-granular granite represents 
a separate intrusion in the porphyritic granite, although the two textur- 
ally unlike rocks are essentially identical in all other respects. 

Over most of the belt the granite shows more or less distinct evidence 
of the effects of intense dynamic-metamorphism, in many instances re- 
sulting in the partial or complete development of a secondary schistose 
structure. In the thin sections of the rock from those areas in which 
the granite appears massive to the unaided eye, more or less pronounced 
effects of pressure-matamorphism are indicated by the microscope. 

Variation in color is from nearly white through the lighter to darker 
shades of gray, according to the proportion and character of distribution 
of the dark minerals, biotite with or without hornblende. To the east 
and southeast of Salisbury, in Eowan County, a beautiful shade of pink 
granite is quarried in several places over Dunns Mountain and its south- 
west extension. In the even-granular granite the texture varies from 
fine to medium, rarely coarse. 



THE VARIETIES OF BUILDING STONES. 151 

Mineralogically, the granites are hardly without exception mica-bear- 
ing (biotite) with, in several places, considerable hornblende associated 
with the biotite. At a number of localities in the southern and northern 
parts of Mecklenburg County, hornblende constitutes the principal acces- 
sory in the granite with only a small amount of biotite noted. In still a 
few other places over the belt, muscovite is sparingly developed as a 
primary constituent in association with the biotite in the rocks. 

Microscopically, the most noteworthy feature of the granites in this 
belt is the large percentage of plagioclase feldspar present in the rocks. 
Only in a few sections does plagioclase occur in very subordinate amount, 
while in most of the thin sections studied this constituent is in large 
amount equalling or even exceeding the potash feldspars. The extinc- 
tion angles measured on the twinning lamallse indicate either a very 
acid oligoelase or albite or both as the species of plagioclase feldspar 
present. Both orthoclase and microcline are generally present and fre- 
quently in nearly equal proportion. A majority of the thin sections 
studied indicated an overlapping in the periods of crystallization of the 
feldspar and the quartz, in the rather numerous areas of micrographic 
intergrowths of the two minerals. Micropoikilitic structure is invariably 
partially or well developed in the feldspars, the inclusions consisting 
largely of feldspar species different from the host, and quartz. This 
structure seems oftentimes best developed in those sections of the gran- 
ites which show the largest development of the micrographic inter- 
growths of quartz and feldspar. The usual primary and secondary ac- 
cessory minerals common to granites are noted in the rock. 

Weathering of the granites as well as the other types of the rocks is 
widespread and profound over the area, yielding the usual decayed 
products common to such rocks. In case of the granites the early stage 
of weathering is represented by a very light gray granitic sand, in which 
the principal minerals of the fresh rock manifest but slight chemical 
decay and are readily distinguished in the decay. This stage is char- 
acterized, as a rule, by very slight or no oxidation and is largely the 
result of physical agents producing the disintegration of the rock. The 
advanced stage of decay consists of a highly oxidized, deep red, fer- 
ruginous, gritty clay, in which the minerals of the fresh rock are usually 
not distinguishable. The product represents an advanced stage in 
weathering promoted largely by chemical agents producing crumbling 
by decomposition. Between these stages of weathering of the granites 
all intermediate gradations may be readily traced. The result of 
this weathering is that, with some exceptions, the rocks both granite 
and other types are usually mantled to some depth with a loose, 



152 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

residual decay. However, outcrops of the firm and hard moderately 
fresh granite are by no means uncommon over the area, and, as a rule, 
the exposures are large enough to admit of the opening of large quarries 
without much stripping. 

Within the limits of the Main Granite Belt are found large quantities 
of very desirable stone well suited for many purposes for which granite 
is used. The belt is traversed in nearly all directions by lines of rail- 
road which offer ready and ample facilities for transportation and make 
quarrying possible in any county within the limits of the belt. 

THE WESTEKJST PIEDMONT GNEISS AND GRANITE BELT. 

GENERAL DESCRIPTION. 

The rocks of Western Piedmont North Carolina are composed largely 
of schists and gneisses of the mica type. These show considerable varia- 
tion in composition and texture where examined and are probably to be 
referred in large part to sedimentary origin. A part of the gneisses, 
however, are certainly altered igneous masses whose structural re r 
semblances to sedimentary masses are due to the effects of dynamo- 
metamorphism. 

Besides these there are areas of both acid and basic igneous rocks in- 
vading the gneiss-schist complex. Among the acid type of igneous rocks 
are massive and schistose granite covering workable areas over many 
parts of the belt. The more important areas of these rocks are found 
in Surry, Wilkes, Alleghany and Alexander counties. There are other 
areas in other counties in this belt, but as far as known, they are of little 
economic importance. 

At present granite quarrying in this belt is limited exclusively to 
Surry County, where in the vicinity of Mt. Airy, the county-seat, one of 
the largest quarrying industries in the State is being rapidly developed. 
In Alexander, Wilkes and Alleghany counties are found extensive areas 
of very desirable granite for certain grades of work which doubtless will 
be developed in the near future. 

SURRY COUNTY. 

The principal outcrops of granite in Surry County are found in the 
northern part of the County near the Virginia line, in the vicinity of 
Mt. Airy, the county-seat. The granite outcrops in flat-surface exposures 
immediately to the north and south of the town of Mt. Airy, and is ex- 
posed in an advanced stage of decay in places within the limits of the 
town (see PI. XIX). 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XIX 




THE VAKIETIES OE BUILDING STONES. 153 

Quarrying on rather an extensive scale has been conducted for some 
years in the exposures found a short distance north of Mt. Airy, and 
to-day it forms one of the most active quarrying Centers in the State. 
The entire quarry operations are under the control of one company, 
known as the North Carolina Granite Corporation. 

THE NORTH CAROLINA GRANITE CORPORATION (MT. AIRY QUARRIES). 

These are the only quarries worked in Surry County and they are 
located J to 1 mile northeast of Mt. Airy. The quarries were first 
opened in 1889, in which year the Mt. Airy Granite Company was in- 
corporated, and the first shipment of stone from the quarries was made 
in July, 1890. The quarries were operated by the Mt. Airy Granite 
Company from the very beginning up to the first of January, 1898, when 
the property was leased to Thomas Woodroffe & Sons, who operated the 
quarries continuously up to July 1, 1904. In July, 1904, the entire 
business was sold to the North Carolina Granite Corporation, which is 
now actively engaged in developing and operating the business. The 
accompanying tabular statement shows the amount of stone shipped from 
these quarries in carload lots from 1890 to 1904 inclusive * (PI. XXIV). 

Shipments of granite from the Mt. Airy Granite Quarries, 1890 to 1904 • 
Year. Carloads. 

1890 135 

1891 264 

1892 334 

1893 523 

1894 952 

1895 834 

1896 548 

1897 1044 

1898 1333 

1899 1474 

1900 1113 

1901 . 1055 

1902 1138 

1903 1203 

1904 1282 

The openings are made in a forty-acre tract of nearly continuously 
exposed granite over the slope and top of a long hill, which rises in 
elevation about 125 feet above the valley-bottom, in which a railroad 
track is laid and operated between the quarries and Mt. Airy. The bulk 

* Through the courtesy of Mr. Thomas Woodroffe. 



154 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

of the granite exposed over this tract has been stripped. The deepest 
working has a depth of about 30 feet from which four or five raises of the 
rock of different thicknesses have been removed. In other openings only 
two raises have been worked, and, over most of the exposure, only the 
first raise (surface) has been made (Pis. I and XX). These will vary 
in thickness, affording quarry-faces which range from 10 to 12, 5 to 6, and 
3 to 4 feet in depth, respectively. In August, 1903, a new opening was 
being worked for blocks and curbing on top of the hill and near the 
northern limits of the exposure, which showed a quarry face averaging 
3± feet in depth and 315 feet long (Fig. A, PI. XXI) . 

The average angle of slope of the exposed granite from the base to the 
top of the hill is 12 degrees, which is readily taken advantage of in 
facilitating easy quarrying. The distance between extreme openings in 
an east-west direction is 2,300 feet. In addition to the 40-acre tract to 
which the quarrying operations are confined, the Company owns more 
than 200 acres over which the granite outcrops but in which no openings 
have yet been made (see PI. XIX). 

The rock is a very light gray nearly white biotite granite, of medium 
texture, containing no visible injurious minerals. Feldspar, quartz, and 
biotite characterize the rock megascopically. The biotite is not, except 
in one opening, equally . distributed through the rock, but is entirely 
absent from some parts; is uniformly distributed through others and 
shows a marked tendency to segregation areas in still other parts of the 
granite. Quartz-feldspar areas of extreme whiteness, ranging from sev- 
eral inches to as many feet in diameter, from which all biotite is entirely 
absent or only a few shreds are occasionally noted, are frequent through 
the rock. This unequal distribution of the characterizing accessory ren- 
ders the stone in places less uniform in color than might be desirable for 
some purposes. Where uniformity of color obtains, the rock is most 
pleasing in appearance and forms excellent and desirable stone for all 
purposes to which granite is put, except for monumental stock, in which 
the contrast of color is not great enough between the cut and polished 
faces. 

In the recent opening made on top of the hill and near the northeast 
limits of the exposure, these irregularities are almost entirely absent and 
the color of the granite is quite uniform, affording a high grade of 
granite for general building purposes. 

Veins and dikes usually found in most granites are nowhere visible in 
the Mt. Airy quarries, and visible jointing is almost entirely lacking. 
The granite is tight in the mass and when quarried yields or breaks, with 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XX 




THE VARIETIES OF BUILDING STONES. 155 

perhaps one or two exceptions, along an irregular twisted or warped 
quarry-face. 

Microscopical Examination. — Under the microscope thin sections of 
the Mt. Airy granite show the presence of the usual granite minerals, 
such as quartz, feldspar, light and dark micas, zircon, apatite, epidote, 
chlorite, and very little iron oxide. Both the quartz and the feldspar are 
in relatively large size individuals, the interstitial areas between which 
are filled, in one of the sections, by a fine-grained mosaic of the same 
mineral, suggesting peripheral shattering from pressure metamorphism. 
Orthoclase is in excess of microcline in all of the sections examined, ac- 
companied by a large proportion of a finely striated acid plagioclase. 
The large quantity of both acid plagioclase and microperthite will doubt- 
less account for the large excess of soda over potash in the analysis of 
the granite given below. Zonal structure and Carlsbad twinning are 
beautifully developed in some of the feldspars. Quartz is of the usual 
granite kind, and forms occasional intergrowths of micro graphic struc- 
ture with feldspar in all of the sections. Biotite is deep brown and 
strongly pleochroic and is altered to chlorite, a colorless mica, and some 
epidote. Much muscovite as an alteration product derived from both 
the feldspars and biotite is present (see Fig. A, PI. II). 

The composition of the Mt. Airy granite is indicated in the following 
chemical analysis : M 

Analysis of granite, Mt. Airy, N. C. 

Si0 2 70.70 

A1 2 3 16.50 

Fe 2 3 2.34 

MgO 0.29 

CaO 2.96 

Na 2 4.56 

K 2 2.45 

FeS 2 0.09 

Total 99.89 

The crushing strength of this granite is well shown in the following 
tests 35 made on specimens of the stone by different parties and at dif- 
ferent places : 

(I) Crushing tests made on specimens of the Mt. Airy granite 

34 Lewis, J. V., Notes on Building and Ornamental Stone, First Biennial Report of 
the State Geologist, 1891-1892 (1893), p. 94. 

35 Furnished through the courtesy of Mr. R. Percy Gray, Greensboro, N. C, President 
of the Mt. Airy Granite Co. The entire interests of this Company were sold in July, 
1904, to the North Carolina Granite Corporation. 



156 



BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 



at the U. S. Navy Yard, Washington, D. C., April 16, 1896 ; Charles 
O'Neil, commander U. S. Navy and Bureau of Ordnance U. S. Navy; 
(II,) at the testing department of the Philadelphia Scale and Testing 
Machine Works, Philadelphia, Penna., Nov. 4, 1895 ; Eiehle Bros. 

Crushing strength of Mt. Airy granite. 
(I.) 



Marks. 


Size of block. 


Crushed at. 


Strain per square inc 


M. A. 1 


2" cube. 


80,725 pounds. 




20,488 pounds 


M. A. 4 


2" " 


86,450 




21,292 


M. A. 7 


2" " 


90,780 




22,469 


M. A. 10 


2" " 


84,410 




20,686 


M. A. 13 


2" " 


80,000 




19,703 


M. A. 16 


2" " 


74,870 
(II.) 


Mean 


18,384 
20,497 




Size of 
block. 


Crushed at. 




Strain per 
sq. inch. 




2" cube. 


79,000 pounds. 




19,750 pounds 




2 // « 


80,350 




20,088 




2" " 


81,600 




20,400 



Mean 20,076 
Specimens broke suddenly with loud report, several large pieces and a 
lot of fine material resulting from each test. 

Two tests, made by Professor P. P. Yenable, of the University of North 
Carolina, at Chapel Hill, October 24, 1895, as to the capacity of the 
Mt. Airy granite for absorbing water, yielded the following results : su 

No. 454 No. 455 

Weight when dried 830.4 1001.7 grams. 

Soaked in water 24 hours and then allowed to 

dry in air 24 hours. Weight 830.8 1002.1 

Weight of water absorbed in 24 hours 0.4 0.4 

As Professor Yenable remarks, neither sample shows noteworthy 
porosity nor absorbing power for water. 

The tests enumerated above, both physical and chemical, made on 
specimens of the Mt. Airy granite amply suffice to show the marked re- 
sistance of the granite to the normal atmospheric forces, and its durability 
when placed under such conditions. Eesults from microscopical exami- 
nation of thin sections of the granite are in accord with these tests. 



bli Furnished through the courtesy of Mr. R. Percy Gray, Greensboro, N. C, President 
of the Mt. Airy Granite Co. ; since July, 1904, known as the North Carolina Granite 
Corporation. 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXI 




A. NORTH CAROLINA GRANITE CORPORATION'S QUARRY, MT. AIRY, SURRY COUNTY, SHOWING 
THICKNESS OF SHEETS WORKED. 




ROCKY-FACE MOUNTAIN, 4 MILES NORTHEAST OF HIDDENITE, ALEXANDER COUNTY, AN UNRE- 
DUCED RESIDUAL OF GRANITE-GNEISS. 



THE VARIETIES OE BUILDING STONES. 157 

The Company is well equipped with all necessary modern machinery 
and appliances for quarrying and handling the stone. The present 
owners of the quarries, the North Carolina Granite Corporation, are 
making some very extensive improvements. In 1905, a large stone cut- 
ting plant was being erected, which will be equipped with the most 
modern stone-breaking appliances. The present expenditure for these 
improvements will approximate $75,000, with ample provision made 
for future development of the enterprise. The stone is handled from 
the quarries to the railway cars by a system of inclined cable-ways, the 
stone being sent down the hill to the cars by gravity. The railway cars 
are operated over a track at the foot of the hill near the quarries and 
the town of Mt. Airy. The limit of dimension stone is the capacity of 
the railroad cars. Blocks weighing 20 tons are reported to have been 
frequently shipped from the quarries (see Pis. I and XIX). 

The granite from the Mt. Airy quarries is marketed over a large ter- 
ritory as attested by the following principal points to which it has been 
shipped for use in both the rough and the dressed state: Many of the 
principal cities and towns in Pennsylvania, of which Philadelphia is 
the largest market ; Cincinnati and Manchester, Ohio ; Baltimore, Mary- 
land; Washington, D. C; many of the principal cities and towns in 
Virginia and North Carolina; and to Memphis and other towns in 
Tennessee. In Plate XXII there is shown the entrance to Greenwood 
Cemetery, Lancaster, Pa., which is built of Mt. Airy granite. 

All the stone used in the large dry dock at Newport News, Virginia, 
the largest dry dock in the world, and the concreting material used in 
the Fort Caswell fortifications, Cape Fear Eiver, North Carolina, came 
from the Mt. Airy quarries. The bulk of the granite from these quar- 
ries, however, is reported to be used in the form of blocks and curbing 
for street purposes. Much of it is also reported to be used for general 
building purposes. Further uses of the granite have been in the form 
of cemetery curbing, street crossings, and railroads for bridge coping. 
The quarry-waste is utilized for concreting, roofs on cotton mills, 
macadam on streets and roads, ballast along the railroads, and in gran- 
ulithic work. Eesults of tests of this rock for road material are given 
on page 266. 

The method of quarrying the stone consisted, in August, 1903, in 
drilling a hole about 3 inches in diameter perpendicular to the surface 
to a depth of the thickness of the stone desired, usually 5 to 7 feet, 
and then fired by a succession of light blasts, using in the first charge 
about a handful of blasting powder. The operation is begun by discharging 
about ^ of a pound of dynamite in the bottom of the hole. This small 
12 



158 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

charge of dynamite pulverizes the stone slightly at the bottom 
of the hole and forms a small chamber. The tamping is then 
cleaned out of the hole, and the hole is recharged in the same man- 
ner, this time, however, using about a handful of powder. 
Recharging of the hole is continued with small charges of powder until 
a small seam has been started at the bottom of the hole, extending 
parallel with the surface. This is found out by using a small steel rod 
bent at the lower end and sharpened to a point, and passing it up and 
down the hole until the crack is located. After the crack has once been 
started, the use of light charges of powder is continued, increasing the 
charges gradually as the seam is found to extend in all directions from 
the lift hole, until the crevice extends a distance of 75 feet or more 
from the hole. The use of explosives is discontinued and a water-tight 
connection is made to the hole by cutting off a piece of iron pipe 
of suitable length, which is fastened in the hole with melted sulphur. 
To this connection is attached an ordinary hand force pump 
and water is pumped into the crevice already formed by the explosives. 
No difficulty is found in extending the crevice by continuous pumping 
of the water until final] y it covers an area frequently as much as two 
acres in extent, and finds vent or relief by tearing out to the thin edges 
on the side of the hill. This process is used in the warmest weather 
when the surface of the rock is naturally somewhat expanded and more 
easily raised. It is very doubtful whether this method could be em- 
ployed to work the stone during cold weather. Experience shows that 
hotter the weather the easier it is to work the stone in this manner. 
No difficulty is had in raising sheets of the stone in this manner cover- 
ing areas of from one to two acres and from 6 to 8 feet in thickness 
close to the hole. After the pump is once started it requires only a few 
hours of steady work to force the sheet out to the thin edge. It is 
found necessary to entirely clean off a ledge of stone made in this 
manner before attempting to form or raise another sheet on the surface 
below. For this reason the quarries cover considerably more area than 
one having natural seam beds (see PI. XXIV). 

Although the North Carolina Granite Corporation found that the 
substitution of water under pressure for powder after the cleavage has 
extended some little distance from the drill hole was an improvement, 
they were not satisfied and experimented with compressed air, with the 
result that they found that compressed air was as much of an improve- 
ment over water as the water was over powder. The method of em- 
ploying compressed air is described by Mr. Thomas Woodroffe, vice- 
president of the company, as follows: 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXII 




THE VARIETIES OF BUILDIXG STONES. 



159 



In the center of the sheet or area to be lifted a drill hole 2 to 3 
inches in diameter is sunk 6 to 8 feet in depth, depending on the 
greatest thickness of stone required, and the operation is continued by 
the discharge of successive small amounts of powder similarly as 
described under the method of quarrying by using water until the 
crevice extends a distance of 75 feet or more from the hole in all 
directions. A pipe is then cemented into the hole and connected by 





Fig. 2. — Diagrams illustrating method of cleaving granite by means of compressed 
air. B, lift or drill hole ; BC, area cleared by powder ; AFF, area cleaved by com- 
pressed air ; DE, thin edge on down-hill side of quarry where air escaped. 



means of a globe valve to an air pipe line from an air compressor. 
Compressed air at 70 to 80 pounds pressure is gradually admitted and 
the cleavage rapidly extended until it comes out upon the hillside in a 
thin edge as indicated by the cross-section, figure 2. A sheet of 
several acres in extent may be raised in this manner, affording a bed 
plane approximately horizontal, to which the quarrymen can work, thus 
securing stone of any required thickness. The first time compressed 
air was used a pressure of 80 pounds was admitted into the cavity 



160 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

which had previously been extended to a distance of 100 feet from the 
lift-hole. The power of the air, however, was too great for the easily 
splitting stone and the cleavage turned abruptly to the surface. In 
the next hole, however, the compressed air was admitted very gradually 
and the stone could soon be heard cracking in all directions and in about 
half an hour the cleavage came to the surface of the hillside as a 
thin edge some 225 feet from the lift-hole. To extend the cleavage by 
means of powder for a hundred feet would require from 6 to 12 days, 
arid with water from 3 to 5 hours, while with the compressed air the 
larger area was split in half an hour. 

It is probable that this is the only quarry at the present time in 
which compressed air is used to split granite in this manner and it 
is a saving both of time and expense. By this and other economical 
methods of operation the North Carolina Granite Corporation is able 
to produce granite for building and paving purposes at a price com- 
paring favorably with any quarry in the country. At the present 
time this is the largest and best equipped quarry in North Carolina 
and the market for its stone is constantly extending every month and 
wherever used, is giving good satisfaction. In Plate XXIII A is a 
general view of the power-house, cutting sheds and offices of the North 
Carolina Granite Corporation and in Plate XXIII B is an interior 
view of the cutting shed. 

ALEXANDER COUNTY. 

ROCKY-EACE MOUNTAIN GRANITE AREA. 

Only one area of granitic rocks in this County is considered, namely, 
Kocky-Face Mountain, which is located about 6 miles northeast of 
Taylorsville, the county-seat, and about 4 miles north of Hiddenite. 
The so-called mountain is an elongated dome-shaped mass of granite- 
gneiss rising to an elevation of not less than 500 feet above the sur- 
rounding plain and measuring about 4 miles around the base. It is 
reported to contain something less than 1,000 acres. The slopes are 
not entirely uniform but are in all cases quite steep. Scattered clusters 
of cedar and pine have taken root in places over the rock-surface where 
a scant but sufficient soil is formed, and the bared rock is very gen- 
erally covered with lichens. The ridge has an approximate northeast- 
southwest trend (see Fig. B, PI. XXI). 

The area is composed of a residual of biotite granite gneiss of light gray 
color and medium texture made up of alternating dark and light colored 
layers. The darker colored bands contain most of the black biotite and 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXIII 




GENERAL VIEW OF POWER HOUSE, CUTTING SHEDS, AND OFFICES OF THE NORTH CAROLINA 
GRANITE CORPORATION, MT. AIRY. 




B. INTERIOR OF CUTTING SHED OF THE NORTH CAROLINA GRANITE CORPORATION. 



THE VARIETIES OF BUILDING STONES. 161 

the lighter colored ones consist chiefly of quartz and feldspar through 
which are distributed more or less scattered shreds of the biotite. Eed 
garnet in small grains and crystals is a frequent mineral in the rock 
in places. The banding is of irregular thickness though generally 
averaging thin. A few narrow quartz veins, which are contorted and 
crushed from pressure-metamorphism, were observed penetrating the 
rock in places. Jointing is spaced at wide intervals and is not a con- 
spicuous structural feature. The strike of the joint-planes observed was 
N'. 30-° E., and N. 80° E. 

Microscopical Examination. — Microscopic study of a thin section of 
this rock shows a biotite granite-gneiss of medium texture. The micro- 
scope displays an interlocking aggregate of quartz and feldspar in which 
pronounced evidence of crushing and recrystallization from dynamic 
metamorphism is shown. The principal minerals are orthoclase, micro- 
cline, and microperthitic intergrowths, with scant plagioclase, quartz 
and biotite with the usual accessories, none of which exert any special 
influence on the rock. Micropoikilitic structure is developed in the 
feldspar. 

. The rock is admirably suited for curbing and blocks for street pur- 
poses, and it should prove to be a valuable stone for this purpose. It 
has not been opened except to obtain a few stone for very local use. 
The rock very closely resembles in mode of occurrence, composition, 
texture and structure, the well-known contorted biotite granite-gneiss 
at Lithonia, DeKalb County, Georgia. The Georgia rock has had a very 
extensive market as a street stone and the closely similar Carolina rock 
should prove to be equally desirable. 

A company recently organized in Salisbury, North Carolina, has pur- 
chased the entire area of granite-gneiss and it is expected that develop- 
ments will be made shortly looking to extensive quarrying of the stone. 

Between Taylorsville and the " Mountain," the counts-rock is a 
schist and gneiss of the biotite type, varying in structure from thinly 
laminated to somewhat thickly banded, and which is considerably con- 
torted and crushed. The rock is highly feldspathic in places assuming 
a distinct granite phase, and the schistosity is cut across by wide and 
narrow quartz veins. 

WILKES AND ALLEGHANY COUNTIES. 

THE STONE MOUNTAIN GRANITE AREA. 

Numerous closely grouped large residuals of granite occur along the 
boundary between Wilkes and Alleghany counties, extending into both 
counties a few miles west of the middle western boundary of Surry 



162 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

County. The areas lie partly in the northeastern portion of Wilkes 
County and partly in the contiguous southeastern portion of Alleghany 
County. One of the largest and most prominent of these residuals is 
known as Stone Mountain, located about 20 miles slightly east of north 
from Wilkesboro, the county-seat of Wilkes County; 5 miles a few 
degrees west of north from Trap Hill Post-Office, in the same County, 
and 18 miles northwest of Elkin, the nearest railroad point.. The 
greater part of the granite area is in Wilkes County. Some of the other 
larger residuals in this area are locally known as Little Stone Mountain, 
Cedar Eoek, Wolf Bock, and Beauty Falls Eock. 

The granite residuals are oval or dome-shaped masses which vary in 
height from probably 100 to 600 feet, and in circumference at the base 
measure from probably 2 to 6 and more miles. There are some 8 or 10 
of these residuals characterized by steep, nearly precipitous slopes rising 
from narrow intervening valleys. Both the tops and the slopes are 
usually covered with a scant veneer of soil, sufficient in many cases to 
maintain quite a growth of trees. In many instances, however, both the 
tops and the slopes are entirely bare, exposing the hard and firm though 
partially decayed rock. 

STONE MOUNTAIN EXPOSURE. 

Stone Mountain, the most prominent one of the granite residuals, is 
an oval-shaped mass of granite, 500 to 600 feet high and measuring 
3 to 4 miles in circumference at the base. Its north, south, and 
west slopes are bare of vegetation and the top is practically so. The 
three slopes named are nearly vertical for an elevation of 300 to 400 
feet, while the east slope is less steep, supporting a scant soil clad with 
trees and smaller forms of plant life (see PL XXV). The top of the 
mountain can only be gained from the east side. 

A railroad line has been surveyed from a point near Elkin on the 
Wilkesboro branch of the Southern Eailway to the base of the mountain, 
with some assurance of the line being built in the near future. 

The rock is a light gray, nearly white, medium-grained, biotite gran- 
ite of slightly coarser texture than the Mt. Airy granite in Surry County, 
which it closely resembles in color and other properties. Entirely fresh 
specimens of the rock could not be obtained as the granite had not been 
opened at any point. It is remarkably uniform throughout the whole 
area in both color and texture, though like the Mt. Airy granite, it 
shows a few segregated areas of black biotite, which become somewhat 
frequent in certain portions of the rock. Examination in the field of 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXIV 




THE VARIETIES OF BUILDING STONES. 163 

the residuals indicates a similar granite of the same composition, color 
and texture for the entire area. Like the Mt. Airy granite, it is nearly 
free from joint-planes, not more than half a dozen joints being observed 
in the entire residual. These had a strike of N". 45° E., and N. 45° W. 
All of the larger residuals of the granite in this area are apparently 
characterized by an almost entire absence of the visible jointed structure, 
while the same rock exposed in many places in the neighboring valleys 
is somewhat closely and conspicuously jointed, the planes having general 
northeast and northwest strikes. Local variation in the strike of the 
joint-planes amounting to a few degrees in different places is shown. 

RESUME OF THE GRANITES OF THE WESTERN PIEDMONT GNEISS 

BELT. 

Massive granites are less abundantly distributed over the Western 
Piedmont Gneiss Belt than over some other parts of the State. One of 
the principal localities in the belt yielding rock of this type, which is 
being rapidly developed and which already constitutes certainly one of 
the largest quarrying centers in the State, is near Mt. Airy in Surry 
County. Extending along the boundary between Wilkes and Alleghany 
counties and covering an extended surface in both counties, are ex- 
tensive unreduced residuals of granite not entirely unlike that quarried 
in the vicinity of Mt. Airy. The rock is lighter in color and coarser 
in texture than the Mt. Airy granite but it is a desirable stone for many 
purposes. No developments have yet been undertaken in the area be- 
cause of its rather inaccessibility to the railroads. In the vicinity of 
Taylorsville and Hiddenite, Alexander County, is a large area of very 
desirable granite-gneiss which should prove to be an admirable stone 
for general street work and other purposes, especially in the form of 
blocks and curbing. 

The granites of this belt are all biotite-bearing, usually of light color 
and of medium texture. With the exception of the Alexander County 
area which is a pronounced schistose granite-gneiss, the rocks of the 
other areas studied are massive in structure. Microscopically, they do 
not differ essentially from the granites of the more eastern areas of the 
State. The large amount of striated plagioclase, albite or oligoclase 
or both, is a noteworthy feature. No injurious minerals are observed, 
and, as a rule, the rocks possess marked strength and durability and are 
very desirable granites for certain grades of work. 

The entire belt, as the name signifies, is one composed largely of 
gneisses of variable composition and texture, which in many places 
could be quarried and utilized to advantage in certain classes of work. 



164 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

THE APPALACHIAN MOUNTAIN GKANITE AREA. 

GENERAL DESCRIPTION. 

In North Carolina, the Appalachian Mountain region includes an ir- 
regular mountainous area lying between the steep southeastern slope of 
the Blue Kidge and the northwestern slope of the Great Smoky moun- 
tains. The region has an approximate area of 6,000 square miles and 
an average elevation over all parts of its surface of 2,700 feet. Many 
of the peaks, however, rise to elevations of more than 5,000 and 6,000 
feet, and Mt. Mitchell, the highest one, has an elevation of 6,711 feet." 

The principal rock-types include gneisses, schists, slates, limestones, 
quartzites, and conglomerates, cut in places by basic eruptive rocks. 
Areas of granite and granite-gneisses are not uncommon. 

The quarrying of the granitic rocks in the mountain region has been 
confined to a few areas of gneiss favorably located to obtain rock prin- 
cipally for road construction and to a less extent for rough work, such 
as street purposes and retaining walls in some of the local towns. Such 
openings have been made in and around Asheville, in Buncombe County, 
and recently in Henderson and McDowell counties. 

In Madison County, North Carolina, and the contiguous part of 
Cocke County, Tennessee, a large area of dark colored, medium-textured, 
epidote-biotite-granite extends southwest from near Hot Springs which 
promises well, but as yet it has not been opened. The unique variety 
of granite known as unakite is associated with the above rock in the 
Hot Springs area, but so far as the examination of the Madison County 
area reveals, the true unakite probably does not occur in workable 
quantities (see Pis. Ill and VI). 

BUNCOMBE COUNTY. 38 

A number of quarries have been worked in the vicinity of Asheville 
to obtain rock principally for road purposes. Massive granites do not 
occur, and at every point where opened the rock is a pronounced schist 
or gneiss of the biotite type. Gradation is from typical mica-schist to 
quartz-schist through distinct fine-grained layers or bands of biotite 
gneiss of granitic composition. Outcrops are numerous along the roads 
leading from Asheville and along the steeper slopes of the ridges. The 
residual decay is extensive in places covering the rocks to some depth, in 
which the schistosity of the original fresh rock is entirely preserved. One 

"Holmes, J. A., N. C. Geol. Survey, Bull. No. 8, 1899, p. 25. 

38 Keith, Arthur, Geologic Atlas of the United States, Cranberry Folio, North Caro- 
lina-Tennessee. 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXV 




THE VARIETIES OF BUILDING STONES. 165 

of the best exposures of decay seen in the County was in an excavation 
being made at the club-house near the entrance to the Battery Park 
grounds where the details of structure were entirely .traced in the decay 
of the mica-schist. 

With possibly several exceptions, the rock is wholly unsuited for any 
purpose save for macadam and ballast, and it is usually of inferior grade 
for even the former purpose. Some of the stone from the Howland 
quarry was used in the chimneys of the building in Overlook Park on 
Sunset Mountain. Crushers are located at each one of the quarries for 
grading and sizing the rock for the use made of it. 

THE ASHEVILLE GNEISS AREA. 
THE CITY QUARRY. 

This quarry is located within the eastern limits of the city of Ashe- 
ville. It was first opened about 12 years ago and has been continuously 
worked to the present time. The main opening is 215 feet in length, 
100 feet wide and 80 feet deep. The rock is an irregularly banded fine- 
textured biotite-gneiss of dark gray color. Garnet is quite freely dis- 
tributed through the rock in thin layers or lenses » and as scattered dis- 
seminated small grains and crystals. 

The layers are tilted at moderately steep angles rather closely cut by 
vertical joints in places, and the rock shows more or less effect of crush- 
ing from pressure-metamorphism. It has been used almost exclusively 
for street macadam, which is about the only use that can be made of it. 

Microscopical Examination, — Under the microscope a thin section of 
the City quarry rock indicates a very fine-grained aggregate of quartz 
and feldspar, with a large percent of biotite now almost completely altered 
to deep reddish brown opaque masses filling the original places of the 
biotite. Some intergrown shreds of muscovite with biotite and scattered 
grains of black iron oxide occur. The parallel arrangement of the mica 
and its alteration products along definite lines, producing the schistose 
structure so characteristic of the rock, is very pronounced. The feldspar 
is largely orthoclase, which contains some inclusions and is more or less 
altered. Quartz predominates and the grains are often crowded with 
hair-like inclusions of rutile. Undulous extinction is marked in some 
of the quartz-feldspar grains. 

THE HAMILTON QUARRY. 

Between \ and J of a mile south of the City quarry, an opening in the 
same rock has been worked in a very steep slope and the rock used for 
macadamizing a private road near Asheville. The rock is in every re- 



166 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

spect similar to that worked at the City quarry described above, except 
that it is probably not quite so thinly schistose. Besults of tests of this 
rock for road material are given on page 265. 

THE BILTMORE QUARRY. 

About 2 miles southeast of Asheville and some 500 paces away from 
and on the north side of the Swannanoa River, considerable stone has been 
quarried in a high nearly precipitous bluff facing the river. The rock 
is quite variable in structure and composition, but is the same as that 
described above within the city limits of Asheville. It was used for 
macadam on the roads in the vicinity of Asheville. 

Microscopical Examination. — A thin section of the rock indicates, 
microscopically, a very fine-grained biotite gneiss in which the parallel 
arrangement of the minerals into bands is marked. The mineral grains 
complexly interlock and are composed largely of quartz, potash and 
plagioclase feldspars, and biotite, the latter mostly altered to a reddish 
brown opaque mass. Additional alteration of the biotite is into chlorite, 
a colorless mica, and some epidote. Much iron oxide, some pyrite, and 
an occasional zircon inclusion complete the list. 

THE MONTFORD QUARRY. 

This quarry is located near Eiverside Park about 2 miles west of Ashe- 
ville, immediately on the west side of the French Broad Eiver. The 
opening is a large one, made in the high and steep bluff facing the river. 
It is a similar rock to that described above, and in 1903 and prior thereto 
it was quarried and crushed for use in macadamizing the roads in the 
vicinity of Asheville. The quarry is now owned by the Balfour Quary 
Company and the principal use made of the stone is for railroad ballast. 
Results of tests of this rock for road material are given on page 265. 

THE COUNTY QUARRY. 

On the Sapphire road and on Beaverdam Creek, about 4 miles west 
of Asheville, a large opening has recently been worked in a moderately 
high and steep slope facing the stream. The rock consists principally 
of a highly quartzose gneiss of fine texture, and in places it contains 
much biotite. Veins of pegmatitic composition penetrate the rock in 
the quarry at irregular intervals. The stone was quarried by the county 
convicts and used for macadam on the roads. 

Microscopical Examination, — Under the microscope a thin section in- 
dicates a rock of granitic composition with much biotite. Orthoclase, 






THE VARIETIES OF BUILDING STONES. 167 

microcline, and plagioclase make up the feldspathic constituent. The 
larger feldspar and quartz grains show much peripheral shattering in 
the fine-grained mosaic of the two minerals, largely quartz, filling the 
interspaces between the larger individuals of these minerals. Biotite is 
present in large amount, usually containing inclusions, and much altered 
to chlorite and iron oxide. More or less muscovite is associated with 
the biotite. Pyrite and garnet are sparingly distributed through the 
sections. 

THE DUBOSE QUARRY. 

About 6 miles northeast. of Asheville, immediately on the east side 
of the Sapphire road, stone was being quarried in August 1903, by the 
county convicts for use in macadamizing the roads. The opening is a 
large one, approximating in size that of the city quarry. The rock is 
a mica-schist, grading in places into a true gneiss. It is quite felds- 
pathic and contains thin, irregular lenses of garnet, which mineral is 
further disseminated through portions of the rock as single small grains 
and crystals. 

THE HOWLAND QUARRY. 

The Howland quarry is located about %\ miles a few degrees north 
of east of Asheville, just below Overlook Park, on Sunset Mountain, and 
it is immediately on the car-line. The rock varies from a mica-schist to 
a pronounced biotite gneiss of dark gray color and fine texture. Further 
variation is from thin to fairly coarse banding in structure, and with 
marked variation noted in texture. It is the same rock as that worked 
at the City quarry, displaying similar evidence of crushing and inter- 
section by rather closely spaced vertical joints. Its principal use has 
been for ballast and road macadam, with a little of it used in the main 
building in Overlook Park on Sunset Mountain. Eesults of tests of this 
rock for road material are given on page 265. 

Numerous other smaller openings have been made in favorable out- 
crops of the same rock in and near Asheville, and the stone has been 
used for a similar purpose as that described above under the several 
quarries. 

SWAIN COUNTY. 

THE BRYSON CITY GRANITE AREA. 

About \\ to 2 miles west of Bryson City, in a cut on the Murphy- 
Asheville branch of the Southern Eailway, occurs a medium coarse- 
textured light gray biotite granite-gneiss, exposed for a distance of nearly 



168 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

half a mile. The granite is in contact with a mica-schist, the schistosity 
of which is cut across by the granite, plainly indicating the intrusive 
character of the latter rock into the schist. The schistosity of the gran- 
ite-gneiss has a different strike from that of the schist. 

The granite-gneiss is variable in structure from nearly massive to 
completely schistose. It is fairly uniform in color and is intersected 
at rather close intervals by joints, although moderate size blocks of the 
stone are possible by careful selection. The rock has not been worked, 
but should prove a desirable stone for ordinary uses, such as street 
work, etc. 

Microscopical Examination. — A thin section of the rock from near 
Bryson City, in the Southern Eailway cut, shows under the microscope 
a completely interlocking aggregate of potash feldspars and quartz with 
biotite and a very little striated plagioclase. Extensive shattering of 
the quartz and the feldspar from dynamic forces is abundantly manifested 
throughout the thin section in a finer-grained mosaic of these minerals, 
and by the characteristic strain shadows on the larger individuals. 
Dust-like inclusions, arranged in some cases along lines which may or 
may not be parallel and in other cases uniformly dotting all parts of the 
host, characterize both the quartz and the feldspar. Biotite is consider- 
ably altered to chlorite and epidote. The usual inclusions of apatite 
and zircon are noted. 

Mcdowell county. 

THE MARION GNEISS AREA. 

One-half mile southeast of Marion, the county-seat, about 300 feet 
above the valley bottom, is an exposure on the mountain side of a variable 
gneiss. It is situated on the north slope of the mountain, which is 
moderately steep though not too steep for a wagon road. The rock is a 
biotite augen-gneiss, of a light gray color, and usually of fine texture. 
It is closely intersected by vertical joints, spaced from a few inches to 
5 and 7 feet apart, striking K 45° E., and N". 45° W. The rock contains 
very many areas of segregated black biotite, some disseminated scattered 
grains of pyrite and is penetrated by a few narrow quartz veins and 
stringers. 

Microscopical Examination. — Microscopically, a thin section of the 
rock shows a very fine-grained biotite-gneiss of granitic composition, in 
which the parallel arrangement of the minerals producing the schistose 
structure in the hand specimen is well developed. " Eyes " of potash 
feldspar, in which the micropoikilitic structure due to inclusions of 



THE VARIETIES OF BUILDING STONES. 169 

idiomorphic feldspar, are sparingly distributed through the fine-grained 
mosaic of interlocking quartz and feldspar grains. Quartz forms the 
most abundant mineral in the section. Both potash and plagioclase 
feldspars are present; the former in excess of the latter. 

Biotite occurs in aggregates of fine shreds and single filaments, largely 
altered to an opaque reddish brown mass. There is considerable epidote, 
and some chlorite. Orientation of the biotite shreds in the direction of 
the longer diameters is pronounced. Strong pleochroism characterizes 
much of the epidote. Areas of micrographic intergrowths of quartz and 
feldspar are rather common, distributed about the borders of some of 
the feldspar " eyes." These larger feldspar individuals show much 
alteration into muscovite and kaolin. 

A small amount of curbing has been quarried from the exposure and 
used on the streets in Marion. The town has purchased a crusher and 
is quarrying the rock for street purposes, which is practically the only 
use that can be made of it. Eesults of tests of this rock for road mate- 
rial are given on page 266. 

HENDERSON COUNTY. 

THE BALFOUR GRANITE AREA. 

The principal quarry opened in Henderson County is located near 
Balfour station, several miles north of Hendersonville, the county-seat, 
known as the Balfour Quarry Company's quarry. 

THE BALFOUR QUARRY COMPANY'S QUARRY. 

This quarry is located three-fourths of a mile northeast of Balfour 
a station on the Spartanburg-Asheville branch of the Southern Railway. 
Two openings have been made about 75 paces apart, the larger one of 
which is about 100 feet by 50 feet, and worked to a depth not exceeding 
25 feet in the deepest part. The smaller opening will measure about 
60 feet by 30 feet and 6 feet deep. The openings are made in flat- 
surface exposures of the rock usually covered by an average depth of 
5 feet of the decayed rock. 

The rock is a light gray medium-grained, biotite augen-gneiss, and 
quite uniform in both color and texture. A few scattered areas of biotite 
segregations were observed in places in the rock. It is very thinly but 
perfectly schistose, the thin bands showing marked parallelism with 
each other. The biotite is not uniformly distributed through all portions 
of the rock but occurs in rounded aggregates of plates occupying distinct 
areas of knife-edge thickness along planes parallel to the schistosity, 



170 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

squeezed out into more or less eye-like areas on the schistose planes. 
The " augen " of feldspar are quite variable in size. The jointing is 
spaced at wide intervals striking N. 40° W., and N. 45° E. 

Microscopical Examination. — The microscope shows the rock to be a 
biotite granite-gneiss composed of the minerals quartz, orthoclase, micro- 
cline, microperthitic intergrowths, plagioclase, light and dark micas, 
zircon, apatite, epidote, and chlorite. The large quartz and feldspar 
grains are completely enveloped in a fine-grained mosaic of these two 
minerals as a result from shattering by dynamic forces. The fine-grained 
mosaic makes up most of the section, the grains of which are complexly 
interlocking. Quartz-feldspar intergrowths in the form of micrographic 
structure are quite freely distributed through the section. The feldspar 
shows the usual alteration to muscovite and some kaolin. Biotite occurs 
in aggregates of fine shreds and single filaments of varying degrees of 
orientation, and it is much altered to chlorite, a colorless mica and 
epidote. 

The rocks work well and nearly any size dimension stone can be quar- 
ried. Blocks of the stone measuring 4 by 8 by 10 feet are easily quarried. 
It has been used chiefly for railroad ballast and to some extent for road 
material. A rock crusher is operated at the quarry for sizing and grad- 
ing the stone for the use made of it mentioned above (see p. 266). 

TRANSYLVANIA, JACKSON AND MACON COUNTIES. 

Beginning near Toxaway in the southwestern part of Transylvania 
County, crossing the extreme southern part of Jackson County and the 
southeastern part of Macon County to within 10 miles of Franklin, an 
extensive granite area is indicated principally in the form of scattered 
large bosses of residuals of granite, locally called mountains. Some of 
the principal ones of these bosses are Mt. Toxaway (Great Hogback 
Mountain), Little Hogback, Sheep Cliff, Double Top, Shortoff, Cow 
Rock, Whiteside Mountain, and Devil's Court House. The slopes and 
tops of many of the bosses of " mountains " are bare and the slopes are, 
as a rule, very steep and precipitous, though affording many excellent 
quarry sites. 

The granite outcrops in many places in the little village of Highlands, 
and it is observed in many places along the Highlands-Franklin wagon- 
road, but the country rock for the most part is a varying schist, probably 
of sedimentary origin. Similar outcrops of granite are exposed along 
the Franklin- Andrews wagon-road and are traced to within a distance 
of 9 or 10 miles from Franklin. 



THE VARIETIES OF BUILDING STONES. 171 

As a rule, the rock is a fine-grain, light gray, biotite granite; usually 
quite massive though, in places, especially near the contacts with the 
country rock, it is more or less foliated or schistose. Jointing is fairly 
well developed though not conspicuous, and is widely spaced readily ad- 
mitting of the quarrying of dimension stone. The color is generally 
quite uniform, varying from light to medium dark gray. 

Nowhere over the area has the rock been systematically quarried, but 
openings have been made here and there to obtain granite for local use, 
such as near Toxaway Inn, at Highlands, and at Whiteside Mountain. 
The area is a large one the limits of which have not been traced out 
though containing many square miles, and it would prove to be of more 
or less importance were the transportation facilities favorable. It is 
doubtful whether the rock could be used for the best grades of building 
and monumental stock, but it would undoubtedly prove to be a desirable 
stone for use in curbing, piers, blocks and all classes of street work, and 
foundations. 

MADISON COUNTY. 

THE HOT SPRINGS GRANITE AREA. 

Beginning about 5 miles southwest of Hot Springs and extending in 
a general southwest direction along the Tennessee-North Carolina bound- 
ary, in Madison County, North Carolina, and Cocke and Sevier counties, 
Tennessee, is an extensive area of granite, lying mostly in North Carolina 
so far as exploited. The exact limits of the area were not traced by the 
writer, but it was traversed for a distance of approximately 6 by 7 miles. 
Keith 39 has recently denned the limits of this area in the Asheville folio, 
which he maps as quite irregular but extensive. 

The area forms a part of the rough mountainous region of western 
North Carolina and eastern Tennessee and it is difficult of access. The 
elevations above sea-level range between 2,500 and 4,500 feet. The 
nearest railroad point is Hot Springs, a station on the Salisbury-Knox- 
ville branch of the Southern Eailway. Outlet from the area to the 
railroad is over very rough mountain trails and roads, the winding, 
circuitous routes of which make it difficult to reach the nearest railroad 
point from the center of the area in less than 10 miles. 

Two types of granite are found in the area, both of which contain 
epidote as a characterizing mineral. The main type of the rock is a dark 
pink green epidote-biotite-granite of coarse texture and somewhat schis- 

39 Geologic Atlas of the United States, Asheville Folio, North Carolina-Tennessee, 
U. S. Geol. Survey, 1904. 



172 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

tose structure. It varies from a typical schistose granite in which 
quartz is present in the usual amount to a nearly quartzless rock of 
the same color and texture — a variation from granite to syenite. Both 
the color and the texture are quite uniform over the area. Outcrops are 
rather numerous along the streams and the ridge-slopes but they have 
nowhere been opened. Jointing seems not to be conspicuously developed 
in any of the outcrops examined. 

UNAKITE. 

The second type of granite occurring in this area is the unique and 
beautiful variety of granite known as unakite, composed of yellow-green 
epidote, dull pink or red feldspar, and quartz. So far as could be de- 
termined from the few exposures of the unakite seen, its occurrence is 
probably in the form of narrow veins penetrating the epidote-biotite- 
granite described above. The unakite where observed is not uniform 
in color and composition but shows pronounced gradations into a highly 
feldspathic rock of pink color on the one hand and an epidote rock of a 
yellow-green color on the other. The several phases of the rock here 
described usually occur in the same " vein," the unakite proper occupying, 
as a rule, the middle portion and grading toward the sides, next to the 
enclosing granite, into either a feldspathic or epidotic rock or both. The 
typical unakite portions of the " veins " show a coarse massive rock of 
even texture and of a light pink and green color. 

The exposure best showing the relations between the unakite and the 
unakite-bearing rock seen was along Eoaring Fork, a short distance 
above its entrance into Meadow Fork. At this point the vein character 
of the unakite seemed apparent. The other exposures of the unakite 
examined were almost entirely covered by decay obscuring any contacts 
between it and the enclosing rock, and therefore revealed little or nothing 
of the real relations of the two rocks. It is quite possible that careful 
detailed study of the area will prove unakite to be in part at least a 
possible phase of the unakite-bearing rock; but it is not found over the 
area traversed in workable quantities and cannot be regarded as of serious 
commercial importance. This statement applies strictly to the area in 
question and workable masses of the epidote granite may or may not 
exist in other parts of western North Carolina and the contiguous part 
of Tennessee. 

Microscopical Examination. — Under the microscope the unakite-bear- 
ing granite is composed of the usual granitic minerals, such as orthoclase 
and microcline in nearly equal proportions, a little plagioclase, quartz, 



THE VAKIETIES OF BUILDING STONES. 173 

occasional biotite, zircon, apatite, rutile, magnetite, and a few small 
grains of pyrite. The secondary minerals are a colorless and a green 
mica, epidote, chlorite and kaolin. 

The epidote is clearly an alteration product derived from the inter- 
action of the ferro-magnesian constituent and the feldspar. It occurs 
in the form of minute microscopic granules, thickly crowded together 
in large and small areas in the feldspar, next to the biotite when the 
latter is present. The quartz contains innumerable long lines of thread- 
like inclusions of rutile, broken into very many minute segments but 
always perfectly aligned. In addition to the epidote the feldspar altera- 
tion into a colorless mica almost completely obscures, in a few instances, 
the original mineral. 

Some peripheral shattering is manifested in the small interstitial areas 
and the narrow border zones of a fine-grained mosaic. The effect of 
dynamic forces is further shown in strain shadows and lines of fracture 
in the quartz and feldspar. In some cases the larger feldspar grains ate 
much fractured and the lines are filled with another mineral; at other 
times alteration has progressed along these lines and patches of deep 
green mica is developed in them. 

A thin section of the unakite under the microscope shows a moderately 
coarse-grained granite composed of orthoclase, quartz and epidote with 
titaniferous iron oxide largely altered to leucoxene, rutile inclusions, 
and secondary muscovite. The quartz and feldspar individuals are con- 
siderably fractured, and they show additional strain shadows with some 
peripheral shattering, indicative of intense dynamic deformation. 

The epidote in the unakite from this area shows from its mode of 
occurrence and association in the thin sections that it is entirely a sec- 
ondary or derived mineral and not primary. It occurs in large masses 
composed of minute microscopic granules, replacing the entire feldspar 
individuals in many instances; and as continuous and irregular discon- 
nected bands and areas of both large and small size, following the 
fractures in both the feldspar and the quartz, but more extensively devel- 
oped in the feldspar. The development of epidote along the breakage 
lines is continuously traced in many cases from the larger areas or masses 
replacing the entire feldspar individuals across or into contiguous feld- 
spars. In still other cases the feldspar shows scattered granules of epidote 
over its surface. All gradations between these two extremes of epidotiza- 
tion appear. Hardly any of the feldspar in the sections examined was 
entirely free from some epidotization. 

Besides epidote, the other mineral matter consists mostly of quartz, 
13 



174 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

which sometimes fills the cracks in the larger quartz and feldspar grains 
made by the fracturing. Some of the less epidotized feldspar shows ad- 
ditional alteration into a colorless mica and some kaolin. No plagioclase 
and no ferro-magnesian minerals were recognized in any of the sections 
of the unakite. 

GRANITE IN OTHER COUNTIES OF THE MOUNTAIN REGION. 

Previous work by the North Carolina Survey 40 on the minerals and 
the ore-deposits of the mountain region indicates that similar areas of 
granite rock to some of those described in this report, principally gneisses, 
occur in other of the mountain counties of the State. Many of these 
areas upon investigation will doubtless prove to be of some economic 
importance and value. Both mica and hornblende varieties of the rock 
are reported. 

Eecent work in the State on the Cranberry folio by Keith 41 of the 
IT. S. Geological Survey shows the occurrence of somewhat extensive 
areas of granites and derived granite-gneisses in parts of Mitchell, Cald- 
well, Watauga and Ashe counties. According to Keith, these rocks are 
considerably metamorphosed from dynamic forces and are now largely 
schistose in structure. Both the even-granular and the porphyritic facies 
are developed. Variation in color is from nearly white, through different 
shades of gray to deep reddish pink; and in texture from medium fine, 
even-granular to coarse porphyritic. The principal minerals are quartz, 
potash and plagioclase feldspars, biotite and muscovite with the usual 
accessories. Much epidote and chlorite are present at times as secondary 
minerals derived from the alteration of the feldspars and micas. Mr. 
Keith assigns these rocks, which include the Carolina gneiss, Eoan gneiss, 
Cranberry granite, Blowing Eock gneiss and the Beech granite, to the 
Archean. He regards much of the rock over the area as suitable for 
building and ornamental stone and states that the Eoan gneiss and 
Cranberry granite have already been utilized for chimneys, foundations 
and bridge piers. Dimension stone is obtainable of uniform color and 
texture, and some of it is described as taking " a handsome and durable 
polish." In many places over the area large and extensive exposures of 
the rock occur affording desirable locations for quarries. The stone with- 
stands weathering quite well as indicated in the natural exposures. 

40 See the various reports on these subjects issued by the N. C. Geol. Survey. 

41 Keith, Arthur, Geological Atlas of the United States, Cranberry Folio, North Caro- 
lina-Tennessee, U. S. Geol. Survey, 1903, pp. 2-8. 



THE VARIETIES OF BUILDING STONES. 175 

In addition to the granitic rocks described in this area, volcanic rocks 
of both acid and basic types are described, some of which are referred to 
as of commercial valne. 

RESUME OF THE GRANITES OF THE MOUNTAIN REGION. 

Granites, both massive and schistose in structure, are quite widely 
distributed over parts of the mountain region of the State. More often 
the granites are schistose in structure and they are usually biotite-bear- 
ing. Additional large areas of gneiss occur of variable composition and 
texture, well illustrated in the vicinity of Asheville, Buncombe County, 
where many openings have been made and much of the stone has been 
quarried for local use, principally, as macadam for the roads and streets, 
and to some extent as ballast. Gneisses of both sedimentary and igneous 
origin occur. In addition to the acid rocks, massive and schistose types 
of basic igneous rocks are met with in places over the region, and in 
some instances they are found in large enough quantity and of such 
character as to make them of value for certain uses. 

To the southwest of Hot Springs, in Madison County, North Carolina, 
and Cocke County, Tennessee, is an extensive area of biotite-epidote 
granite of pleasing dark green and mixed yellow color, which in connec- 
tion with its other good qualities should prove to be of economic im- 
portance. The so-called unakite found in association with this rock does 
not exist in workable quantities and it has only scientific interest. The 
area is rather inaccessible and could only be developed at considerable 
cost. 

No quarrying of a systematic kind has yet been undertaken at any 
point in the mountain region, but numerous small openings have been 
made in exposures of the rock in many places, located usually very near 
some town or railroad, and the stone has been used entirely for local 
purposes. Some of the granites of the region are accessible and can be 
quarried, while other areas of the rock could only be developed at an 
increased cost of production because, principally, of inaccessibility to 
transportation facilities. 



CHAPTER III. 

DIKES AND VEINS PENETRATING THE CRYSTALLINE 
KOCKS OF NORTH CAROLINA. 

Intersecting materials of several different types, indicating marked 
variation in composition and texture, have wide distribution over the 
crystalline area of the State. These include, beginning with the most 
acid, true quartz veins, pegmatite, aplite and granite dikes, of normal 
composition and texture; and abundant dikes of basic igneous rocks of 
which diabase and diorite are perhaps the commonest types. Textural 
differences among these rocks are those usually characteristic of the rock 
types enumerated. 

In width the dikes and veins may vary from several inches to several 
hundred yards with marked variation indicated on the strike. All the 
types named have been observed penetrating the granites as well as the 
other more important and extensive rocks forming the crystalline com- 
plex. The most recent rocks in the State yet noted intersected by the 
dikes are the triassic sandstones. 

A list of those dikes of basic composition whose trend has been ob- 
served is given below in tabulated form. The list is by no means com- 
plete as it includes only the more important basic dikes in the areas 
traversed during the past field season. These are described elsewhere 
in this report separately by counties in connection with the granite. 
Fuller petrographic description and lithologic relations of these rocks 
will probably be published later when more detailed studies of the crys- 
talline rocks of the State are made. 

It will be observed from the diagram below that of the total number 
of dikes recorded 73, more than half, 44, lie in the northwest quadrant. 
Of the remaining ones 15 lie in the northeast quadrant; 13 have a 
north-south strike, and one has an east-west strike. The variation in 
the northwest quadrant is from N. 10° W. to N. 50°-60° W.; and in the 
northeast quadrant from N. 20° E. to N. 45°-50° E. 

Comparing these observations with similar and more detailed ones 
by Shaler on Cape Ann, Massachusetts, we find the principal direction 






DIKES AND VEINS PENETRATING THE CRYSTALLINE ROCKS. 177 

or the quadrant containing the largest number of dikes to be the same 
for the two widely separated areas, namely, the northwest quadrant. 
Of the 361 dikes observed on the Cape, Professor Shaler records 266 
that lie in the quadrant between northwest and north. 1 

In the case of the North Carolina dikes here recorded, composition 
seems not to have been a guiding principle as to cutting direction, for 
it is observed that those of the diabase type, which are the most common, 
cut in several directions. 

JOINT STRUCTURES. 

The recorded observations on jointed structure in this report were 
almost entirely limited to the quarries, since the prevailing decay of the 
rock did not permit, as a rule, of sufficiently accurate results in observing 
the jointing in the natural exposures of the rocks. There are, however, 
some exceptions to this statement to be noted. In the large exposures 
of granite the rock is usually hard and firm, sometimes nearly fresh 
though more or less discolored from partial weathering, in which the 
joint-planes, when sufficiently developed, could be as accurately observed 
as in the quarries. Such an example is furnished in the granite ridge 
known as Dunns Mountain occurring 4 to 5 miles east and southeast 
of Salisbury, in Eowan County. Numerous openings are made at ir- 
regular intervals on the ridge, but the inter-quarry areas are sometimes 
free from accumulated residual decay and the rock surface is hard and 
firm, in which the jointing is well developed and can be accurately 
measured. 

The observations here recorded extend over the entire State where 
granites occur, hence the number of observations is fairly large. The 
examination of the list reveals two principal sets of jointing, namely, 
in the northeast and northwest quadrants, respectively, with quite fre- 
quent jointing in places in two other directions, east-west and north- 
south. In the northwest quadrant the direction of jointing varies be- 
tween N. 10° W. and "N. 80° W., with precisely the same extremes in 
the strike noted for the northeast quadrant. It will be further noted 
from the tabulated list of the joints given below that the greatest number 
has its planes in the northwest quadrant. Of the minor sets of joints 
striking north-south and east-west, nearly equal distribution obtains for 

1 Shaler, N. S., The Geology of Cape Ann, Mass., 9th Ann. Rept. IT. S. Geol. Survey, 
1887-1888 (1889), p. 580. 



178 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

the two directions, though the north-south direction has several more 
than the east-west ones. 

SLICKENSIDES. 

In most of the quarries where the jointed structure is at all well devel- 
oped the sides of the joints show smooth, more or less polished and 
striated surfaces, indicating considerable relative movement in the rocks 
since the formation of the joints. The striae are usually developed in 
a thin coating of a dark yellow to yellowish green mineral, which prob- 
ably in most cases is damourite, sometimes epidote, or a mixture of the 
two, an alteration product derived from certain original minerals in the 
fresh granite, principally mica, and has resulted from the rubbing to- 
gether of the two sides along the plane. 

DIKES OF BASIC COMPOSITION INTERSECTING THE GRANITES. 

Dikes of basic igneous rocks, principally diabase, have been observed 
penetrating the granites in almost every important area of these rocks 
in the State. Of the total number of dikes recorded, the largest number 
of them has been noted from surface exposures of the rocks, which are 
invariably more or less completely decayed, obscuring any former trace 
of jointed structure in the enclosing rock. Quite a number of the quar- 
ries, however, exposing fresh rock have afforded splendid opportunity 
for noting the relations of the dikes to the structural features of the 
granite. Without exception almost, in those cases where dikes of basic 
igneous rocks were observed penetrating the granites in the quarries, the 
dike follows persistently one of the major sets of jointing. In a number 
of quarries, a half dozen or more dikes in parallel position penetrate the 
granite within the limits of the quarry opening, the largest quarry open- 
ing of which will not exceed 300 feet. 

The widest of these dikes exposed in the granite openings will not 
exceed 50 feet and they are frequently less than 6 feet in width. In 
those openings noted in the State exposing a number of the dikes, the 
interval at which the dikes cut the granite varies greatly. Within a zone 
of 12 to 15 feet, two or more dikes may occur, always parallel and at 
all times coincident with the jointing in that direction. More often, 
however, the intervals at which the dikes intersect the granite are con- 
siderably greater. The dip of the dikes is vertical or only varies a few 
degrees from vertical, a feature likewise characteristic of the jointing. 
Figs. A and B of PI. V show the position of the dikes in the granite in 
one of the quarries. 



DIKES AND VEINS PENETRATING THE CRYSTALLINE ROCKS. 179 

The following table makes clear the relationship between the strike 
of the dikes and that of the jointing: 

Locality. County. Strike of Dikes. Strike of Joints. 

Charlotte City Quarry Mecklenburg. N. 40° E. N. 40° E., N. 35-50°W. 

One and a quarter miles north of 

Greensboro Guilford. N. 20° E. N. 20° E., N. 50° E., N. 20° W. 

A half mile southeast of Jamestown.. " N. 40° W. N. 40° W. t N. 20° E. 

Half a mile east of Davidson Mecklenburg. N. 15° -20° W. N. 20° W., N. 70° E. 

Three-quarters of a mile southwest of 

Rolesville Wake. N. 20° E. N. 20° E., E.-W. 

One-quarter of a mile north of Liles- 

ville Anson. N. 20° W. N. 20° W., N. 70° E., N.-S. 

ACID DIKES AND VEINS PENETRATING THE GRANITES. 

Unlike the dikes of basic igneous rocks intersecting the granites, those 
of acid composition do not conform to any definite direction in trend 
nor do they appear to be in any way related to the jointing. On the 
contrary, they are found intersecting the granite in directions coincident 
with nearly all points of the compass. They are characterized by equally 
as great variation in width, composition and texture. Under this class 
of intersecting material are included pegmatite, quartz, normal granite 
dikes and occasional aplite. 

Pegmatites. — Pegmatitic veins and dikes are found intersecting the 
granite in a majority of the quarries in the State. They are so numerous 
in portions of some of the quarries that dimension stone is difficult to 
obtain. This is especially true of the Raleigh city quarries of biotite 
granite-gneiss where hardly a block of any size can be quarried that is 
entirely free from the quartz-feldspar veins, a circumstance strikingly 
shown in the State Capitol building in Ealeigh built of this stone. In 
some of the quarries pegmatites are only sparingly developed and in 
others still they are entirely absent. 

Where observed, they are characterized by the usual coarse-textured 
pegmatitic structure, composed principally of coarse crystallizations of 
feldspar and quartz with subordinate stout platy black biotite. The 
feldspars are both pink and white and are highly lustrous with good 
cleavage development, and twinning after the Carlsbad law is frequent. 
Feldspar is the most abundant constituent, the quartz frequently dimin- 
ishing to very subordinate amount. Quartz is usually of the light and 
the dark smoky varieties which, with the pronounced vitreous luster, con- 
trasts sharply with the feldspar. Biotite is usually present in large, 
stout platy forms, at times irregularly distributed between the feldspar 
and quartz, at others distributed along a central axis in the vein or dike. 
Muscovite has been observed in the pegmatite bodies only occasionally, 



180 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

and tourmaline, garnet and the rarer minerals sometimes associated 
with pegmatite are strikingly absent. 

The pegmatites are very extensive in some cases, though usually nar- 
row, apparently deep-seated and of aqueo-igneous origin. Others are 
limited in extent, surrounded entirely by the granite, denoting in such 
cases probably true veins of segregation. In the Ealeigh City quarry 
where the only true aplite has been observed, the aplite and pegmatite 
are associated as banded aplite-pegmatite. As a class the pegmatites 
are irregular in outline conforming to no definite or fixed direction but 
they cut the granite at random and at all angles. 

In the Ealeigh City quarry, the Carrigan quarry, 3 miles northeast 
of Mooresville, in Iredell County, and the Walker quarry, 1^ miles south- 
east of Ridge Summit station, in Guilford County, the pegmatites are 
frequently noted intersecting each other in a faulted condition of several 
inches displacement. 

Aplite. — Aplite dikes have been observed at only one locality in the 
State, namely, in the City quarry at Ealeigh, where they number less 
than half a dozen in all. They do not exceed 6 inches in width, usually 
not more than 2 inches, and in several instances they are in contact with 
pegmatite on one side and with the enclosing granite on the other. 
Megascopically, the aplite is very light in color, composed of a fine- 
grained crystallization of quartz and feldspar, through which are ir- 
regularly distributed subordinate very small flecks of black biotite. 

Microscopically, the aplite is strikingly similar in mineral composition 
to the enclosing granite, except that the former is very fine grained and 
differs only in the former being much finer in texture and containing 
a much smaller proportion of biotite and plagioclase feldspar. The 
mineral composition of the rock would place it with the potash aplites. 

Granite Dikes. — True granite dikes of normal composition and of fine 
texture are very numerous in certain areas of the State. At only a few 
localities, however, have they been observed penetrating the granite 
masses. In several of the granite quarries near Greystone, in Yance 
County, and in a flat-surface exposure of porphyritic granite half a mile 
north of Mount Mourne, Iredell County, fine-textured biotite granite 
dikes have been observed penetrating the granite. The dikes are dark 
gray in color containing much uniformly distributed black biotite in 
minute shreds, with quartz and feldspar. As a rule, they do not exceed 
more than a few inches in width, 4 to 12, and are definitely oriented. 

At Belmont Springs, 1-J miles east of Charlotte, Mecklenburg County, 
the granite is cut by a dike of quartz porphyry spotted with pencils of 



DIKES AND VEINS PENETRATING THE CRYSTALLINE ROCKS. 181 

manganese and iron oxide, from which it has derived the name of leop- 
ardite. A description of the leopardite is given on pages 70-74 of this 
report. 

In the main granite belt of the State crossing in a northeast-south- 
west direction the middle Piedmont region (maps. Pis. Ill and VI), 
granite dikes are quite numerous over many parts of the area. The rock 
of this belt is principally a complex of granite and diorite. 

Numerous small irregular dikes of a fine-textured pink granite con- 
taining but little mica cut the dioritic rock at many localities throughout 
the belt. The dikes are usually irregular in outline and, as a rule, they 
vary only a few degrees from the vertical. They are always of fine 
texture and vary from a few inches to several feet in width (see PL 
V, B). Feldspar of light to deep pink in color invariably predominates. 
The mica is in subordinate amount and is usually of light color. 

In no case were the dikes continuously traced from the rocks which 
they penetrated to the larger granite masses, nor do they resemble in all 
cases the rock of the main granite stocks, but they show less mica and 
are invariably finer grained. In most cases not much doubt exists, how- 
ever, of their real significance. Mainly for the reason that these dikes 
are almost always more numerous near the granite-diorite contacts than 
at some distance away from them, they must be regarded as probable 
apophyses from the main granite masses. No openings have been made 
at any point exposing the fresh rock, but in all cases the exposures are 
in the partially or nearly completed decay of the rocks made by cuts 
along the railroads and the public highways. 

The dikes are not confined exclusively to the dioritic rocks but pene- 
trate others as well, such as the so-called slates around Salisbury along 
the roads leading east and west from the town. 

The principal localities where the granite dikes have been noted are: 
Northeast of Concord in Cabarrus County, for several miles along the 
Concord-China Grove road; near Concord and on the east along the 
Mt. Pleasant road ; along the east and west roads leading out of Salisbury 
a short distance from the town; 5 miles west of Barber Junction in the 
vicinity of Elmwood, Iredell County; in the cuts of the Southern Kail- 
way in the vicinity of Lexington, Davidson County; and again to the 
north and south of High Point, Guilford County, in the railroad cuts. 

Quartz Veins. — Quartz veins of small dimensions cut the granite in 
a number of the quarries, usually in those quarries where pegmatitic 
intrusions are strongly developed. The two sets of intersecting material 
are more or less closely associated. The quartz composing the veins is 



182 BUILDING AND ORNAMENTAL STONES OF NOETH CAROLINA. 

of the usual clear vitreous kind generally found filling such veins. They 
are not numerous in any of the openings, and, as a rule, they do not 
measure more than a few inches across. 

Quartz veins of large dimensions are numerous over the crystalline 
area of the State. They are readily traced over the surface for consider- 
able distances in many cases by the partially disintegrated outcrops and 
the abundant fragments which litter the surface. In cross-section they 
vary from 25 feet to several hundred }''ards. In some localities the veins 
are sufficiently large to render the quartz of some local value in road 
construction. In other localities these veins form true fissure veins, are 
metalliferous, and mark many of the most important gold and copper 
mines in North Carolina. 

RELATIONSHIP BETWEEN THE JOINTING AND THE DIKES. 

The statements here made apply more particularly to the dikes of 
basic composition. The observations on these structures seem com- 
prehensive enough to warrant some general statements which may be 
more closely followed in future work in the State to ascertain whether 
a fixed relationship does obtain. Kef erring to the tables recording the 
strike of the joints and the dikes, a marked parallelism is observed in 
certain directions between the joints and the dikes. The planes of most 
of the joints are in the northeast and northwest quadrants. Likewise 
the strikes of most of the dikes are in the same quadrants. Moreover, 
in nearly every quarry where basic dikes are exposed, the strike of the 
dikes and that of the joints for a given direction is coincident, apparently 
indicating that for those cases, at least, the jointing has exercised some 
influence on the cutting direction of the dike. Not only is this true for 
the dikes penetrating the granite in various quarries but it is also true 
of the Triassic sandstone belt where the same relation between joints 
and dikes obtains. Whether this will apply in general to the dikes 
beyond the limits of the fresh rock exposures it is not possible to say 
though presumably it does, since the jointing is entirely obscured by the 
deep residual decay covering the fresh rock. 

For reasons stated below the basic dikes of the State, so far as they 
have been observed, do not all belong to the same period of intrusion 
but are to be referred to different ages. The observations recorded de- 
noting coincidence in the direction of dike and that of joint, include 
both the massive, unaltered igneous intrusive and the perfectly schistose 
more or less altered basic dike. If these observations are correct, clearly 
the jointing in the granites antedates the intrusion of the basic rocks 
forming the dikes. 



DIKES AND VEINS PENETRATING THE CRYSTALLINE ROCKS. 183 

AGE RELATIONS OF THE BASIC DIKES. 

Over many parts of the crystalline area where basic dikes are noted 
penetrating the rocks, strongly contrasted structural differences in the 
dike rocks obtain. Many of them are entirely massive and unaltered, 
bearing no evidence of pressure metamorphism; while a large number 
of them are more or less perfectly schistose and are otherwise mashed 
and closely jointed, which caused them to separate into small rhomboidal 
blocks. The ferro-magnesian constituent in the latter is usually much 
altered. Both classes of dikes often intersect original massive igneous 
rocks that are now more or less schistose in structure, induced by pressure 
metamorphism. 

These facts afford a strong basis for regarding the basic dike rocks to 
be of different periods of intrusion and therefore of different age. The 
massive dikes intersecting the more or less schistose igneous rocks must 
post-date the period of disturbance inducing the schistose structure in 
the enclosing rock; and likewise the schistose dikes were intruded at 
an earlier period and prior to the metamorphism of the enclosing rocks, 
for the field evidence indicates that the schistose structure in the two 
rocks is the result of the same forces. 

Until the age of the granites or other enclosing rocks is definitely 
fixed, the exact age of the more schistose dikes must remain conjectural. 
These must antedate the period of pressure-metamorphism affecting the 
enclosing rocks for both dike and enclosing rock are similarly affected. 

The Triassic sandstone occupying the eastern marginal position of 
the Piedmont pleateau region in the State are, as in the case of the 
granites, cut by typical massive diabase dikes. These dikes conform to 
an approximate northeast direction. Nowhere in the State have the dikes 
been observed to intersect or penetrate rocks younger than the Triassic 
sandstones. Their age is accordingly definitely fixed as late Triassic or 
Jurassic, and they are correlated with the flows of the same composition 
in New Jersey, New York, and the Connecticut Valley region, and with 
similar dikes in Virginia and Georgia to the north and south of the 
Carolina area. The dikes of the Carolina sandstone belt are traced into 
the neighboring crystalline rocks of the plateau, where they have wide 
distribution over the entire crystalline area of the State. Beyond the 
limits of the sandstone belt in the crystalline areas penetrated by dikes 
of basic igneous rocks, close similarity in texture, structure and composi- 
tion of the massive dikes to those of the sandstones, and their relations 
to the enclosing crystalline rocks make it reasonably certain that they 
are of the same age as those intersecting the Triassic sandstones. 



184 



BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 



TABLE SHOWING THE DISTRIBUTION AND STRIKE OF THE DIKES 

OF BASIC ERUPTIVE ROCKS OF THE MAIN GRANITE BELT OF 
THE PIEDMONT PLATEAU REGION. 

Locality. County. Strike. Width in ft. 

Charlotte City quarry; a number of parallel dikes Mecklenburg. N. 40° E. 3 + 

East limits of Charlotte; two parallel dikes " NE.-SW. 25-100 

East limits of Charlotte (Belmont Springs) " NW.-SE. 100 + 

Four miles east of Charlotte " 6-25 

Eight and a half miles northeast of Charlotte " N. 10° W. 200 + 

Five miles northeast of Charlotte " NW.-SE. 50 + 

Nine miles north of Charlotte (2 miles north of Newell).. " N. 20° W. 150 + 

Ten miles north of Charlotte (3 miles north of Newell).. " N. 20° W. 

One mile west of Charlotte; two parallel dikes " N. 20° E. 12 

One-half mile east of Davidson " N. 15° W. 10 + 

Two and a half miles east of Davidson " NE.-SW. 25 + 

One and a quarter miles southwest of Davidson " NW.-SE. 100 + 

East limits of Concord Cabarrus. N. 30° E. 25 ± 

One mile east of Concord " NW.-SE. 100 + 

One mile north of Summit Siding " NW.-SE. 

Six miles southwest of Concord (Rocky River) " NW.-SE. 50 + 

Three miles east of Salisbury Rowan. N. 20° W. 

Three miles south of Faith village " N. 30° W. 500 + 

Four miles southwest of Faith village " N.-S. 4 + 

Seven miles northwest of Salisbury " NW.-SE. 15 ± 

Eight miles northwest of Salisbury " N.-S. 25± 

Nine miles northwest of Salisbury " N.-S. 6 ± 

One and a half miles south of Cooleemee Cotton Mills... " E.-W. 25 ± 

Two miles south of Cooleemee Cotton Mills " NW.-SE. 9± 

One mile northwest of Mooresville Iredell. NW. -SE. 6 ± 

Three-quarters of a mile west of Oaks Ferry Davie. N. 20° -30° E. 100 

One mile west of Oaks Ferry " N. 30° E. 8 

One and a quarter miles west of Oaks Ferry " NE.-SW. 100 + 

Three hundred yards north of the Hairston residence " NE.-SW. 100 ± 

Three hundred yards north of the Hairston residence " NE. -SW. 100 ± 

One-half mile north of the Hairston residence " NE.-SW. 

Five miles south of Winston-Salem Forsyth. N. -S. 35 ± 

Northwest limits of Salem " N. 20° E. 200 + 

One and a half miles east of Winston-Salem " N. 5° -10° W. 25 ± 

Three-quarters of a mile southwest of Bethania " N. 20° E. 200-500 

One mile west of Greensboro Guilford. NE.-SW. 100 + 

One mile west of Greensboro " NE.-SW. 50 + 

Two and a half miles southwest of Greensboro " NW.-SE. 

Three miles east of Greensboro " NW.-SE. 25 + 

One and a quarter miles north of Greensboro " N. 20° E. 3 + 

One mile southeast of Jamestown; several parallel dikes 

dose together " N. 20° E. 1-15 

Nine miles northeast of Greensboro; several parallel dikes. " NE.-SW. 25-100 

Ten a half miles northeast of Greensboro " N.-S. 200 ± 

Three and three-quarter miles northeast of Greensboro " N.-S. 15 

Nine miles northeast of Greensboro " NE.-SW. 2 

One-half mile southeast of Jamestown " N. 40-50° W. 

Near depot at Jamestown " NE.-SW. 25 + 

Total number of dikes with strike N. 5°-50° + W 20 

N. 20°-40° + E 21 

N.-S 6 

E.-W 1 



DIKES AND VEINS PENETRATING THE CRYSTALLINE ROOKS. 



185 



TABLE SHOWING THE STRIKE OF THE JOINTS PENETRATING THE 
GRANITES OF THE MAIN GRANITE BELT OF THE PIEDMONT 
PLATEAU REGION. 



Locality. County. 

City Quarry of Charlotte Mecklenburg. 

Southeast limits of Charlotte " 

Northeast limits of Charlotte " 

One mile east of Davidson " 

One and three-quarter miles southwest of 

Davidson " 

East limits of Gastonia Gaston. 

One and three-quarter miles north of Gastonia " 

Three miles northwest of Belmont " 

East limits of Concord Cabarrus. 

Southwest limits of Concord " 

Three miles southwest of Concord " 

Rocky River, Fires' Mill " 

Dunn's Mt., north side of Stokes Ferry Road. Rowan. 
North slope of Dunn's Mt., four miles east 

of Salisbury " 

McCanless quarries, five miles southeast of 

Salisbury " 

Rowan Granite Company's quarries, five miles 

southeast of Salisbury " 



Consolidated Granite Company's quarries, 

near Faith village " 

Powlers Mt., nine miles southwest of Salis- 
bury " 

Three miles southwest of Faith " 

Northwest limits of Woodleaf " 

One mile northwest of Mooresville Iredell. 

One and a half miles southwest of Mooresville. " 

Three miles northeast of Mooresville " 

Twelve miles north of Mooresville " 

Cooleemee Cotton Mills Davie. 

Five miles south of Winston Forsyth. 

Five miles southeast of Winston " 

Northeast limits of Greensboro Guilford. 

One and a quarter miles north of Greensboro. " 

Ten and a half miles northeast of Greensboro. " 

One-quarter mile south of Summerfield " 

One-half mile southeast of Jamestown " 

Seven and a half miles northwest of Burling- 
ton Alamance. 

Rocky Face Mtn., six miles northeast of Tay- 

lorsville Alexander. 



N. 40° E. 



N. 70° E. 

N. 20° E. 
N. 40°-60 c 
N. 30° E. 



Strike of Joints. 

N. 35° -50° W. 

N. 10° W., N. 60° W. 

N. 40° W. 

N. 20° W. 

N. 45° W. 
N. 60° -70° W. 
N. 60° -70° W. 
N. 20° W. 
N. 60° W. 



N. 40° E. 

N. 70° E. 

N. 50° E. 

N. 70° E., N. 20° E. 

N. 60° E., N. 25° E. 

N. 15° -20° E. 
'N. 80° E., N. 25° E. 

N. 65° E., N. 20° E. 

N. 45° E., N. 15° E. 

N. 40° E., N. 10° E. 
W N. 35° E. 

N. 80° E. 

N. 40° E. 

N. 10° E. 

N. 30° E. 

N. 60° E., N. 20° E. 



N. 65° E. 

N. 70° E. 
N. 45° E. 
N. 50° E. 



N. 20° E. 

N. 60° E. 

N. 10° E., N. 70° E. 

N. 20° E. 

N. 10° E. 

N. 80° E., N. 30° E. 



N. 40° W. 
N. 40° W. 
N. 25° W. 



N. 30° -40° W. 
N. 70° W. 
N. 50° W. 
N. 45° W. 
N. 40° W. 

N. 50° W. 
N. 40° W. 
N. 30° W. 

N. 70° W. 



N. 65° W. 
N. 45° W. 



N. 45° W. 

N. 45° W. 
N. 80° W. 
N. 40° W. 
N. 20° W. 



N. 40° W. 
N. 20° -30° W. 



N.-S., E.-W. 
N.-S., E.-W. 
N.-S. 



N.-S., E.-W. 

N.-S., E.-W. 
E.-W. 



N.-S., E.-W. 

N.-S. 



N.-S. 


E.-W 


N.-S. 




N.-S. 




N.-S. 




N.-S. 


E.-W 



Total number of joints with strike N. 10° 

N. 10° 

N.-S. 

E.-W. 



30° E. 

ro° w. 



186 



BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 



TABLE SHOWING THE DISTRIBUTION AND STRIKE OF THE DIKES 
OF BASIC ERUPTIVE ROCKS OF THE COASTAL PLAIN AND THE 
NORTHEASTERN PIEDMONT BELT. 

Locality. County. Strike of Width of 

Dike. Dike in ft. 

Western limits of Rockingham Richmond. N.-S. 100 + 

Two and a half miles west of Rockingham " NW.-SE. 25 + 

Three and a half miles west of Rockingham " N.-S. 150 + 

Ten miles north of Wilson, granite quarry Wilson. NW.-SE. 20 

West limits of Wadesboro Anson. NW. -SE. 

One and a quarter miles west of Wadesboro " N.-S. 1 + 

Two and a quarter miles west of Wadesboro; two parallel 

dikes " N.-S. 

Two and three-quarter miles west of Wadesboro; two par- 
allel dikes " N. 35° W. 25 + 

Three miles west of Wadesboro " N. 30°-35° W. 20 

Three to three and three-quarter miles west of Wades- 
boro ; eight or more parallel dikes " N. 20°-35° W. 4-50 + 

One mile northwest of Wadesboro N.-S. 1 + 

One and a quarter miles northwest of Wadesboro; two 

parallel dikes " N. 30° W. 100 + 

One-half mile east of Wadesboro " N. 10° W. 25 + 

One and a half miles east of Wadesboro " N. 10° W. 25 + 

Three miles east of Wadesboro; three parallel dikes N. 20° W. 6 + 

Three and a quarter miles east of Wadesboro; two paral- 
lel dikes " NW.-SE. 25 + 

One mile east of Lilesville " N. 20° W. 25 + 

One and a quarter miles east of Lilesville N. 20° W. 140 

Two miles northeast of Franklinton Franklin. NW.-SE. 

Two and a half miles east of Franklinton " NW.-SE. 

Three and a half miles east of Franklinton " NW.-SE. 300 + 

Four miles west of Louisburg " NW.-SE. 20 f 

One mile north of Rolesville Wake. N. 20° E. ... 

Total number of dikes with strike N. 10°-45° + W 17 

N. 20° E 1 

N.-S 5 









DIKES AND VEINS PENETRATING THE CRYSTALLINE ROCKS. 



187 



TABLE SHOWING THE STRIKE OF THE JOINTS PENETRATING 
THE GRANITES OF THE COASTAL PLAIN AND THE NORTH- 
EASTERN PIEDMONT BELT. 



Roles- 



Locality. 

Fourteen miles north of Raleigh 

Five miles east of Wyatt station 

Three-quarters of a mile northwest of 

ville 

Two miles northwest of Raleigh 

West limits of Raleigh 

East limits of Raleigh 

Tar River at Louisburg 

One-quarter of a mile north of Lilesville 

Two and a half miles south of Wadesboro 

West limits of Warrenton 

Two miles north of Warren Plains 

Contentnea Crk., three miles south of Wilson. 

Three miles north of Elm City (Toisnot) 

One mile north of Rocky Mount 

Greystone quarries, Greystone station 

Two miles north of Greystone 

Three miles north of Greystone 

Northeast limits of Henderson 



County. 




Wake. 


N. 20° E. 


<< 


N. 20° E. 


« 


N. 20° E. 



Franklin. 
Anson. 



Warren. 



Wilson. 



Edgecombe. 
Vance. 



N. 80° E. 
N. 70° E. 
N. 30° E. 
N. 30° E., 
N. 45° E., 
N. 50° E. 
N. 40° E. 
N. 45° E. 
N. 60° E. 



N. 25° E. 



N. 60° E. 
N. 10° E. 



Strike of Joints. 



N. 80° W. 

N. 80° W. 

N. 80° W., N. 20° W. 
N. 20° W. 
N. 60° W. 

N. 60° W. 
N. 70° W. 
N. 80° W. 
N. 80° W. 



E.-W. 
E.-W. 



E.-W. 



N.-S 
E.-W. 



N. 30° W. 



N. 45° W. 



N. 70° W. 



E.-W. ; 
E.-W. 
E.-W. 



N.-S. 
N.-S. 



N.-S. 

N.-S. 
N.-S. 
N.-S. 



Total number of joints with strike N. 10°-80' 

« « « N> 20°-80° 

N.-W. .. 

N.-S. ... 



CHAPTEE IV. 

THE CALCAEEOUS ROCKS: LIMESTONES AJSTD MARBLES. 

VARIETIES. 

Under this head are included a large and variable series of rocks com- 
posed essentially of carbonate of lime alone, or of carbonates of lime 
and magnesia, though frequently rendered quite impure through the 
presence of clayey matter, iron oxides, free silica or silicate minerals. 
They have originated through the induration and, in some cases, meta- 
morphism of beds of calcareous mud, shell and coral remains formed 
on ancient sea-bottoms. 

Many varietal names are given to these rocks, according as they 
vary in composition, color, structure or even uses to which they are put. 
The terms argillaceous, siliceous and ferruginous, are applied to such as 
carry an appreciable quantity of these substances, similarly as is the case 
with the sandstone. Hydraulic limestone is an impure siliceous and 
argillaceous variety used for making hydraulic lime. Often a part of 
the lime is replaced by magnesia giving rise to magnesian limestones, or 
if the magnesia occurs to the amount of 45.6% of the entire amount, 
the stone is called a dolomite. An oolitic limestone is one in which the 
individual particles are in the form of rounded, nearly spherical par- 
ticles like the roe of a fish. The so-called Bedford (Indiana) stone is 
of this type, but such are not known to occur in North Carolina. A fos- 
siliferous limestone is one carrying fossils; a coral, or shell limestone 
one containing coral or shell remains, etc. Many limestones or dolomites 
have undergone just the right amount of induration, or metamorphism, 
to impart to them such colors and textural qualities as make them de- 
sirable as marbles. In short, a marble, proper, is but a limestone or 
dolomite of such appearance as to make it suitable for decorative, or the 
finer grades of building work. Many marbles are so coarsely crystalline 
and of such color as to unfit them for decorative purposes, but are 
eminently suited for fine structural or monumental work. 

The color of marbles and limestones in general is quite variable. A 
pure limestone or dolomite is white; gray or blue-gray and black colors 
are due to the presence of organic matter, i. e., carbon. The pink and 



THE CALCAREOUS ROCKS : LIMESTONES AND MARBLES. 189 

red or green colors are due as a rule to the presence of iron in some of 
its forms. In many marbles, and particularly the dolomitic varieties, 
the impurities have crystallized in the form of some variety of amphibole, 
pyroxene or mica, or as free quartz, magnetite, iron pyrites, graphite, etc. 
Such minerals as a rule exert a detrimental effect, as noted in the 
chapters on weathering. 

STRUCTURE. 

In structure the stones classed under this head are quite variable. 
Those which have undergone little metamorphism are often so fine- 
grained as to seem quite amorphous and may carry numerous more or 
less conspicuous fossil remains. Metamorphism is invariably productive 
of crystallization, and all grades of texture, from that which is too fine 
to be visible to the unaided eye, to that in which the individual particles 
are an inch or more in length are common. Fig. A, PI. XXVII, shows 
the structure of an ordinary marble, as seen under the microscope. The 
dolomitic varieties are more inclined to a granular structure than are 
the limestones. 

Occasional calcareous rocks are met with in which the beds have been, 
by earth movements, shattered like so much glass and the fragments 
again recemented into a more or less solid mass, forming thus breccia 
marbles which are often of great beauty. Many of the so-called Numid- 
ian marbles are of this t}'pe. In other cases the original limestone beds 
have been broken into fragments and the individual particles tumbled 
about by wave action until more or less rounded like the pebbles on a 
modern beach, and the whole, in the form of a coarse and quite variable 
gravel, once more cemented by calcareous matter to form beds sufficiently 
firm for the production of marbles. The beds of calcareous Triassic 
conglomerate near Point of Eocks and elsewhere in Maryland are of 
this type. 

WEATHERING QUALITIES. 

Pure limestones suffer most severely on exposure through the solvent 
action of rainwater. Nevertheless, as the solvent action goes on very 
slowly, they weather away smoothly and evenly, and rarely become un- 
sightly. With granular types, particularly dolomitic forms, or such as 
are mixtures of dolomite and calcite, a granulation results, the stone 
becoming rough and friable on the immediate surface and ultimately 
falling away to sand. Stones of uneven, laminated structure, naturally 
weather uneventy, some of the layers or laminae giving way before others. 
14 



190 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Included minerals like tremolite are inclined to weather out on the im- 
mediate surface, giving the stone a pitted appearance. Limestones, 
being sedimentary rocks, nearly always show bedding lines, although 
these may be quite inconspicuous in small specimens. Closely adjacent 
beds may vary greatly in color, texture, and quality. t Often good sound 
beds are separated from one another by impure, shaley layers, or layers 
containing so large a percentage of impurities as to make them quite 
undesirable. The omnipresent pyrite is particularly common in lime- 
stones, and in the white varieties is harmful in producing a staining, 
rendered the more conspicuous from the whiteness of the stone. 

METHODS OF WORKING AND QUARRYING. 

Owing to their softness, the limestones and marbles may be cut and 
moulded into a variety of forms, either by hand or machine methods. 
They may be sawn into slabs by reciprocating saws fed by sand, turned 
on lathes, and the more compact varieties highly polished. In quarrying, 
machines are largely used, the blocks being first freed at the sides and 
ends by channelling, and then at the bottom by undercutting or gad- 
ding. Powder or explosives of any kind are never used in quarrying 
high-grade material, as the tenderness of the stone renders it liable to 
shattering, or, at least, to incipient fracture. These matters are suffi- 
ciently discussed elsewhere (see p. 244 and PI. XXVI, B). 

USES. 

The highest grades of marbles are used only in interior decorative 
work and for statuary purposes. For the latter only the white, evenly 
saccharoidal varieties are suited. Such have not yet been found within 
the limits of North Carolina. For interior decoration, the colored 
varieties are most desirable, though the white is also used. In the form 
of balustrades, railings, wainscotings, mantels, and tilings their use is 
almost universal. The coarser varieties find a wide use for the higher 
grades of buildings, this being particularly true of the dolomitic varieties 
like those north of Baltimore in Maryland and in northern Georgia. 
In years past marble was the chief material used for monumental and 
tombstone work, though it is now being largely superseded by granite. 

MARBLE. 

GEOGRAPHICAL DISTRIBUTION. 

Limestone, either in the form of marble or the common compact 
variety, is not an abundant rock in North Carolina. In the southeastern 



THE CALCAREOUS ROCKS: LIMESTONES AND MARBLES. 



191 




192 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

counties of the State, a coarsely cavernous shell limestone is found which 
serves for rough construction in the immediate vicinity. A belt of semi- 
crystalline limestone passes through Catawba, Lincoln, and Gaston 
counties. In McDowell County, and also farther west, in Cherokee and 
Swain counties, are comparatively narrow belts, which have been meta- 
morphosed into the condition of marble. The distribution of these is 
shown on the map ( Fig. 3 ) . The various quarries which have been opened 
along this belt, together with many of the most promising natural out- 
croppings, are described in the following pages, beginning with the most 
southwestern. 

CHEROKEE COUNTY. 

The marble deposit extending through this County from southwest to 
northeast, in the form of a narrow strip varying from 1,000 feet to 
possibly one-half a mile in width, is a continuation of the marble beds 
of Fannin County, Georgia, to the south. The beds vary but little from 
N. 45° E. in trend and dip usually about 50° S. 45 ± E. 

The country rock lying immediately northwest of the marble is a 
mica schist which shows much variation, being sometimes a typical mica 
schist and sometimes a quartz schist. That on the southeast varies from 
a schistose sandstone to a typical quartzite. These rocks withstand 
erosion much better than the marble and limestone, and it is for this 
reason that the marble is generally found in low lying valleys. Thus 
the Valley Eiver follows the marble beds very closely from near Topton 
(Eed Marble Gap) to Murphy, a distance of about 23 miles. The ISTot- 
teley Eiver also follows the marble from the Georgia line to a short dis- 
tance southwest of Murphy. 

The railroads also follow the marble beds, the Southern Eailway from 
Topton to Murphy and the Atlanta, Knoxville, and Northern from 
Murphy to the State line. These features are important factors in the 
consideration of the economic value of the marble. The fact that the 
railroads follow the stone renders practically every foot of the whole 
deposit readily accessible. The rivers, while they may cause more or 
less trouble by overflows and also have caused the stripping to be heavier 
in many instances, are of much importance in that they could in many 
instances be made to furnish power for operating quarries. 

Excepting a small amount of light-pink or flesh-colored stone near 
Eed Marble Gap, the marble is of two prevailing colors — a blue-gray 
more or less mottled and streaked with white, and almost pure white. 



THE CALCAREOUS ROCKS I LIMESTONES AND MARBLES. 193 

In texture the stone varies from a medium to a fine grain, the medium 
grain stone predominating. 

Near the contacts with the country-rock, the marble is very impure, 
containing much tremolite, talc, and in some places considerable quartz 
in the form of small veins and irregular patches. Away from the con- 
tacts the marble is pure, although in some places it does contain more 
or less pyrite. 

An unfortunate feature of all the marble beds of the region is the 
abundance of joints. There are always two series of joints that usually 
trend 1ST. 20°-35° E., and N. 30°-70° W., respectively, varying from one 
inch to a very few feet apart. In addition to those just mentioned, 
there is generally a third and often a fourth series of subordinate joints. 

As a rule, the stripping is quite heavy, sometimes as much as 12 or 
15 feet, usually, however, from 4 to 8 feet. 

The stone, although generally covered with soil, is exposed in many 
places along the streams and, in a few instances in railroad cuts. Also 
at two or three localities, openings were made and small quarries operated 
for a short time, several years ago. These openings and some of the 
characteristic outcrops will be described in detail. 

THE CULBEKSON QUARRY. 

Near this place, which is a flag station on the A. K. & N. Ky., about 
10 miles southwest of Murphy, is a pond of stagnant water around the 
edges of which are great piles of worthless blocks of marble. Some 
machinery, such as derrick, boiler, engine, and other quarry equipment, 
is also on the ground going to ruin. This is what, 12 or 15 years ago, 
was the Culberson Marble Quarry. No stone could be seen in place and 
the following observations were made upon the blocks of waste material 
which, indeed, seems to be the only quality of stone that the quarry ever 
furnished. 

The marble is a crystalline stone of fairly uniform medium grain, 
which in color varies from a dark to a light bluish gray, each color being 
more or less streaked and mottled with the other. The surfaces of prac- 
tically all the blocks show a great many joint planes that intersect in 
such a manner as to cut the whole piece into numerous small rhomboidal 
blocks. These joints are sometimes quite easily discernible, but some- 
times, especially in a freshly broken surface, they are very hard to see; 
but, however inconspicuous, they invariably to a greater or less degree 
determine the manner in which the stone breaks, and after exposure to 
the weather for only a short time, they become quite prominent. 



194 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

Only one block could be found that showed the original surface. This 
surface was simply a net-work of four distinct sets of joints from 1 to 
10 inches apart. 

The quarry was also very unfavorably located, being in a low-lying 
valley at the very edge of a small stream. The stripping was from 4 to 
7 feet, and there was no way of draining the place except by pumping. 
It was, however, well located as regards facilities for shipping, being 
almost on the right-of-way of the A. K. & 1ST. Ey. 

In a cut on this same railroad, about \ mile southwest of 
Kinsey and perhaps 3J miles from the above described place, 
is an exposure of impure marble of fairly fine grain and of a dirty 
white color. The stone, in addition to the impurities, which consist 
of much tremolite, more or less altered to talc, quartz in both small 
veins and irregular patches, and pyrite, is cut by four distinct sets of 
joints. Two of these sets are quite prominent, having a trend of N". 40° 
E. and KT. 50° W., and varying from a few inches to a very few feet 
apart. The other sets, while subordinate, are also very close. 

The impurities are probably due to nearness of the outcrop to the 
contact with the quartzite, since another similar exposure about 150 
yards nearer the station is nearly free from such minerals. Indeed, 
this second outcrop is of much better stone than the first, being a fine- 
grained white marble, fairly uniform in both color and texture. But, 
like the other, it is literally cut to pieces by joints. 

THE KINSEY QUARRY. 

This long since abandoned quarry is located at a small station of the 
same name. It now consists of a hole about 100 feet by 80 feet and 
about 50 feet deep, partly filled with water, and round which are piles 
of discarded marble and a quantity of more or less dilapidated quarry 
machinery. 

The stone is rather coarsely crystalline and the majority of it is of 
a dark blue gray, more or less mottled and streaked with white, although 
much of it is a light gray color and a few blocks were noticed that 
showed a slight tinge of pink interbanded with the light gray. 

The joints are so numerous and close (four sets, two prominent and 
two subordinate, and varying from a few inches to 5 or 6 feet) that it was 
impossible to get enough solid stone to warrant operating the quarry. 

The place for making the opening was ill-chosen, being so located that 
quite an area of land drains into it, and there was no way of getting rid 
of the water except pumping. The stripping also was heavy — from 8 to 
12 feet. 



THE CALCAREOUS ROCKS: LIMESTONES AND MARBLES. 195 

These last features, while very detrimental to profitable quarrying, 
were not the cause of discontinuing the work. This was the closeness and 
prominence of the jointing. 

No openings have been made in the beds between this place and the 
quarry of the National Marble Company at Kegal, a flag station on the 
Southern Eailway about Sy 2 miles northeast of Murphy. Several natural 
outcrops may be seen between the two places, but these are generally small, 
sometimes only a few small boulders, and are of such a nature that they 
afford very little clue to the character of the underlying stone. 

THE NATIONAL MARBLE COMPANY'S QUARRY. 

The only marble quarry in operation in the State is located in the nar- 
row valley of a small creek, a tributary of Valley Eiver, about Sy 2 miles 
northeast of Murphy. The beds of marble in which this quarry is being 
operated have a width of about 300 yards. The stone is of two colors — a 
dark bluish-gray, often streaked and mottled with white although in 
places apparently free from such mottling, and a more or less uniform 
white stone. The gray stone appears to lie between beds of the white. 
The beds have a strike of about 1ST. 45° E. and dip about 50° S. 45° E. 

The country-rock on the south is a calcareous quartz schist, which is 
literally filled with hexagonal crystals of biotite, and which grades grad- 
ually into a very hard and compact sandstone — almost a quartzite. The 
biotite gradually decreases in quantity as distance from the contact in- 
creases and is entirely absent from the quartzite. The rock lying next to 
the marble on the north is a typical mica-schist. The contact is very 
sharp, but the schist nearest the marble is more or less calcareous. Im- 
mediately at this, as well as at the south contact, there is more or less 
tremolite, often in large masses, which, in many instances, is to a greater 
or less degree altered to talc. 

The marble, as well as the country rock, gives evidence of the intense 
dynamic forces to which rocks of the region have been subjected. This is 
shown not only by the jointing, which is very prominent and close, and by 
the secondary minerals developed at and near the contacts, but even by the 
very texture of the marble. The interlocking grains of calcite or dolo- 
mite, of which the stone is composed, are invariably more or less elon- 
gated and always have their longer diameters roughly parallel. This ten- 
dency toward schistosity, if it may be so called, seems to be also parallel 
with the bedding planes of the rock. This texture, while not very promi- 
nent in this particular quarry, is, in some instances, so pronounced that 
the marble is distinctly platy or schistose and consequently worthless as a 



196 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

building stone. This shearing is much less prominent in the blue-gray 
than in the white, which is finer-grained and apparently a more delicate 
rock than the dark-colored stone. This is true, not only of the stone of 
this particular exposure, but also of all the light-colored stone of the 
whole marble deposit. 

There are three distinct sets of joints in the stone of this opening, two 
of which, trending N. 40° W. and N". 20° E. respectively, are quite promi- 
nent. The third set is subordinate but is of sufficient importance to cause 
considerable waste in quarrying. The joints of the two prominent sets 
are from a few inches to a few feet apart, usually 2 to 6 feet. 

The texture of the stone seems to be quite uniform for each color, the 
gray being always of a medium grain and the white always fine. The gray 
marble is said to be used wholly for monuments, headstones, etc. The 
best grade of the mottled marble could probably be used for interior 
decoration, but as a rule, the color is too sombre and monotonous for such 
uses. As a general building stone, this gray marble, if placed upon the 
market, would meet with considerable favor. It is very firm and com- 
pact and contains no injurious impurities. 

The present operations were begun in May, 1902, and have at date of 
writing hardly gotten beyond the exploratory stage (see A and B, PL 
XXVI). The superficial beds were found to be considerably injured by 
erosion channels, which in some instances, were of large size, and in one 
or two cases to extend to depths of from 12 to 18 feet. However, the last 
" floor " which was taken up contained only one small opening of this 
character, and it is probable that no more of them will be encountered. 
Certainly none will be found below the drainage level. Since the open- 
ing is in a low, narrow valley, there is no way of draining except by 
pumping, nor is there any convenient way of disposing of the waste 
material. What little marketable stone has as yet been taken out is said 
to have found a ready market for monumental purposes. The stone is 
shipped in the rough to the marble works of Capt. T. M. Brady at 
Canton, Ga., and there sawed, dressed, and placed on the market. 

The machinery installed consists of one fifteen-ton hoisting engine, four 
Sullivan channelling machines, three Ingersoll gadders, one derrick, and 
one quarry bar. 

Following the marble beds to the northeastward from this place, there 
are found here and there, principally in the stream beds that cross the belt, 
several small outcrops, but of such a nature as to give almost no idea of 
the general character of the stone, except to show that it is still of the two 
prevailing colors before mentioned. In a few places, as on the J. T. 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXVI 









< 



1 A 



A. VIEW OF MARBLE QUARRY OF THE NATIONAL MARBLE COMPANY AT REGAL, CHEROKEE COUNTY. 





-*w*\*«* m^BKBj 



B. QUARRY OF NATIONAL MARBLE COMPANY, REGAL, N. C, SHOWING CHANNELLERS AT WORK. 



THE CALCAREOUS ROCKS: LIMESTONES AND MARBLES. 197 

Hays' property near Tomotla, more or less prospecting has been done at 
different times. In no instance was this prospecting carried any further 
than borings with core drills, and, as far as could be ascertained, nothing 
was found that differed essentially from the stone at Eegal, which has 
just been described. 

During the summer of 1903 Mr. C. W. Meador, of Corinth, Miss., did 
some exploratory work in the marble beds near Marble Station, about 7 
miles northeast of Eegal. Several test holes, located so as to ascertain the 
character of as much stone as possible, were put down. These showed the 
two colors met with elsewhere, arranged in the same order, blue-gray, more 
or less streaked and mottled, stone alternating with light-colored beds. 

The texture and color of the marble, so far as could be determined from 
the work done, is so nearly like that now being quarried at Eegal, that a 
detailed description is unnecessary. 

So far as shown by the records obtained, it appears that the marble beds 
at this place are not quite so thickly jointed as at the localities to the 
southwest. The thickness of the marble beds is much greater here than 
at any other point between this and the State line, the belt being more 
than one-half a mile wide, while the average width heretofore has not been 
more than 300 yards. The dip here is practically the same as at the other 
places, about 40° S. 45° E. The stripping is from 8 to 16 feet, and con- 
sists of soil, clay, and stream wash — boulders and gravel. Since the 
marble occurs in the lowest ground of the region, it is evident that there 
will be more or less trouble from water and also that there will be some 
inconvenience in disposing of waste material. 

The marble beds attain their greatest width, about three-fourths of a 
mile east of the place just mentioned, and retain it with more or less 
variation to perhaps 1J miles east of Andrews, a distance of about 
8 miles. It is within this area that the most promising marble of 
the whole belt is found. The stone throughout the entire area is buried 
to a depth of from 5 to 20 feet, and there are few outcrops, though occa- 
sionally, as near Andrews, there are some fair-sized exposures. The 
largest and most favorable of these occurs in the Valley Eiver bank in 
the eastern limits of the town. 

The marble here is from medium to coarse grain — considerably coarser 
than that at Marble, Eegal, and other places before mentioned. The color 
varies from light to dark bluish-gray. Sometimes the two colors are quite 
uniform, and again both are prettily mottled and streaked with either 
lighter or darker bands. Upon close inspection many small particles or 
specks are seen to be distributed irregularly through the mass of the 



198 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

coarser portions of the stone. Under the microscope these are found to 
be irregularly-shaped pieces of some carbonaceous material, probably 
graphitic in character. These specks are most abundant at and near the 
peripheries of the various interlocking crystals that make up the stone, 
though to a less extent in their interior. To this cause may be ascribed 
the color of the blue-gray stone. A thin section of this stone, when ex- 
amined under the microscope is seen to be made up of numerous medium- 
sized, irregular, clear, calcite granules, which are filled with very small 
particles exactly like the larger ones in the coarser stone, though in this 
case the distribution is much more even. The particles, though more 
numerous at the boundaries of the crystals, are also very abundant in their 
interior. 

This rock also shows the effects of shearing, the various component 
crystals being slightly elongated and arranged with their longer axes 
roughly parallel. However, this tendency toward schistosity is much less 
prominent here than at the other places before described. This stone, 
when compared with that of the other localities, is seen to be remarkably 
free from joints. 

This exposure at Andrews has an area of about 20 by 30 feet, and from 
this two sound blocks each 8 by 10 feet could be obtained. There seem 
to be only two sets of joints. These trend 1ST. 20° or 30° E., and N". 70° 
W., respectively. There is a vertical exposure of about 5 feet and through- 
out this there is little or no variation of texture. The color consists of 
alternating bands and streaks of light and dark. 

Although the beds here have not been exploited, the indications are 
more favorable for sound stone, free from joints than at any point thus 
far examined in the entire belt. The material is perhaps too coarsely 
crystalline to find a wide demand for decorative work, but is apparently 
well adapted for general building and monumental purposes. It is also 
favorably located for quarrying. Stripping would vary from 6 to 15 
feet, and would consist entirely of soil and stream boulders and gravel. 
Shipping facilities are good, the outcrop being only a very short distance 
from the Southern Eailway. It is quite probable also that with some 
expense the Valley Eiver could be made to furnish power for sawing and 
dressing the stone, and probably, for operating the entire plant. 

Dark bluish-gray marble, similar in every respect to the above described 
stone, occurs on Col. Chas. N". Hickerson's plantation, 1-| miles west 
of Andrews. More or less prospecting was done here several years 
ago. This work, it is said, showed that the gray marble, while cut 
by many joints, is probably massive enough for profitable quarrying. The 



THE CALCAREOUS ROCKS : LIMESTONES AND MARBLES. 199 

exploratory work was done with a one-inch diamond drill. It is said that 
cores from 5 to 7 feet long, entirely free from joints, were frequently 
taken out. 

There are also many small exposures of white marble along the Valley 
Eiver on this farm. The stone is apparently exactly like the white mar- 
ble at Eegal, both in color, texture, and also like that stone in the number 
and closeness of the joints. Stripping and facilities for shipping are the 
same as at Andrews. 

Two miles east of Andrews, on a farm belonging to Mr. J. McWhitaker, 
are several exposures of marble which, with one exception, do not differ 
essentially in color and texture from the other outcrops in the vicinity of 
Andrews. The beds are much narrower and the forces of deformation 
seem to have been more intense here than elsewhere, the stone being 
literally cut to pieces by four distinct sets of very prominent and close 
joints, varying from a few inches to 2 to 3 feet apart. 

The exposure referred to above as an exception occurs about one-half 
mile farther east than those just mentioned. The marble here is of medium 
grain and bluish-gray in color. It is peculiar in that there are two sets of 
lines, light and dark, alternating with each other, very close together, 
which intersect in such a manner as to give an indistinct checked ap- 
pearance. 

The beds of this stone, while more or less broken, are apparently in 
much better condition than those a short distance farther down the 
stream, and it is possible that exploration would expose stone that could 
be quarried. 

The outcrop occurs at a spring near a house occupied by a Mr. William 
Young, but is not very favorably located, being nearly a mile from the 
railroad, and in a swampy ground where there is certain to be more or 
less trouble from water. Stripping would also be heavy, and there is no 
convenient dumping ground for waste stone. 

The marble beds, after the flexure or curve just east of Andrews, as- 
sume their usual northeast trend, and with a slight intermission near 
Ehodo, a flag station on the Southern Eailway, are continuous to a place 
one-half mile west of Topton (Eed Marble Gap), where they terminate — 
pinched out as it were. Throughout this distance outcrops may be seen 
here and there, none of which appear at all promising. The stone, while 
sometimes of favorable color and texture, is invariably either broken by 
joints into small rhomboidal blocks, or has been so badly sheared that it 
is more or less schistose or platy — in some instances decidedly so. 

It will be noted that a narrow belt of marble is indicated on the map 



200 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

(p. 191) as lying about 7 miles southeast of the main belt, just described, 
and extending with one or two slight interruptions from Martins Creek 
3 miles northwest of Ballew P. 0. to Peachtree Creek, crossing the Hi- 
wassee Eiver at Brasstown. The stone occurring here has much the same 
color as that in the main belt, but the beds are so badly jointed and con- 
tain so many impurities that it is doubtful if they can be made to yield 
anything of value. 

SWAIN COUNTY. 

Passing over the mountain at Eed Marble Gap, the marble beds are 
next found about one-half mile northeast of Topton. They extend as 
elongated lens-shaped masses, with one or two short intermissions, to 
about one mile northeast of Hewitts, where they are crossed by the 
Nantahala Eiver, beyond which they pinch out. 

The stone in these beds is quite different in color and texture from that 
on the west side of Eed Marble Gap. It varies from a light-gray to almost 
a black, and from a cream-white to a delicate flesh color or pink. Some- 
times both colors are solid; sometimes irregular, alternating bands or 
patches of each occur. In many instances there is a decided tinge of 
green in the rock. This last is due to the development of a secondary 
green mineral, probably serpentine, which varies greatly in the amount 
present, and seems to extend through the rock parallel with the schistosity. 
This combination of various shades of cream and pink, each more or less 
interbanded with green, is very pretty. However, it seems that this stone 
will, as a rule, not acquire as smooth a surface or take as high a polish as 
might be desired. 

This stone is generally decidedly schistose, the platy or schistose struc- 
ture being so prominent in some instances that the stone in weathering 
breaks up into either thin flat plates or into long, narrow blocks resembling 
sticks of cord wood. 

When a thin section of this stone is put under the microscope, the in- 
dividual crystals of the rock are seen to be very much elongated in one 
direction, and to have their longest diameters arranged parallel with each 
other (see A, of Plate XXVII). It is this feature which causes the 
apparent schistosity. Though all the stone of these beds shows this 
schistosity in greater or less degree, the conditions in one or two 
places seem to be such that it might be possible to obtain market- 
able stone. One of these places is on the property of the North 
Carolina Talc and Mining Company at Hewitts Station. The outcrop, 
at which some exploratory work has been done, occurs on the mountain 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXVII 




A. MICRO-STRUCTURE OF MARBLE FROM HEWITTS. SWAIN COUNTY. 




B. MICRO-STRUCTURE OF SANDSTONE FROM WADESBORO, ANSON COUNTY. 



THE CALCAREOUS ROCKS I LIMESTONES AND MARBLES. 201 

side about one-half mile southwest of the station and 300 or 400 feet 
above the railroad. The stone is all fine-grained and in color does not 
differ essentially from that above-mentioned, i. e. a cream white to delicate 
pink streaked and mottled with green, a medium to light steel-gray or 
blue-gray, and a very dark-gray, almost black. It also shows a distinct 
tendency toward the above-mentioned schistosity or " platiness," but not 
to such an extent as to prevent the obtaining of marketable slabs, pro- 
vided the stone be sawed parallel with the schistosity, which, indeed, is 
the proper way to cut it in order to get the best results as regards color. 

This marble contains more or less impurities such as tremolite, pyrite, 
and some quartz. The tremolite is found most abundantly near the con- 
tacts with the country rock, and very sparingly, if at all, in other portions 
of the stone. The amount of pyrite apparently varies with the color of 
the stone — the darker the color, the more pyrite. The quartz occurs as 
irregular elongated patches, as small veins that generally run parallel 
with the schistosity of the rock, and as elongated grains varying greatly in 
size, though usually very small. These impurities are by no means regu- 
larly distributed through the rock. They are all, except the pyrite, most 
numerous at and near the contacts and diminish in quantity as distance 
from contacts increases, so that much of the stone is apparently free from 
them. The pyrite is so abundant in the very dark stone that it is of very 
doubtful value. 

It appears that there are at least two parallel-lying beds of this stone, 
from one of which comes the various shades of gray, and from the other 
the light-colored rock. The thickness of these beds could not be deter- 
mined. However, the following drill records furnished by Mr. F. E. 
Hewitt, manager of the company that owns the marble, will give some 
idea of the relation of the different colors. Both holes were bored as 
nearly as possible at right angles to the schistosity, which is apparently 
parallel with the dip of the beds. 

Hole No. 1. 

1. Bluish gray, mottled and banded with white 20 ft. 

2. Purplish pink, color not uniform, more or less green 

interbanded 12 " 

3. Pink with more or less green, green increasing with depth. 30 " 

Hole No. 2. 

1. Bluish gray 20 or 30 ft. 

2. Pink with some green streaks 8 or 10 " 

3. Purplish pink, mottled with green 20 " 

4. Cream white 7 or 10 " 



202 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

This stone is very favorably located for quarrying. A face of about one- 
fourth mile by 100 feet could be exposed with very little stripping. This 
face would be parallel with the railroad and about 200 feet above it. Thus 
the stone could be easily put upon the cars. Also the Nantahala Eiver 
runs at the edge of the marble beds and parallel with them and could be 
made to furnish ample power for operating a quarry. 

Mcdowell county. 

A great body of limestone, portions of which may be termed marble, 
occurs along and near the North Pork of the Catawba Eiver in the north- 
ern part of the County. The stone extends as a series of usually large, 
disconnected outcrops, from Woodlawn P. O., 10 miles north of Marion, 
to the " head " of North Cove, 15 miles northeast of Woodlawn. 

By far the greater portion of the stone is only a dolomitic limestone of 
varying purity, generally containing such impurities as quartz, tremolite, 
and talcose minerals in small quantity, and sometimes much pyrite, espec- 
ially in the darker portions of the stone. However, often there appears 
to be no other impurity than a small amount of quartz, which occurs in 
irregular grains and as thin veins which represent former joints and frac- 
tures in the rock; and sometimes even this appears to be lacking or 
present in only very small amount. 

Much of this stone, while probably not suitable for high grade work, 
could be used to good advantage as a general building stone, the color and 
texture of the rock, as a rule, being favorable for such uses. However, 
there is one feature of this stone which seriously injures all, and renders 
the greater part of it, absolutely worthless even as a building stone. This 
is the number of, and the closeness of the joints, there being always two, 
generally three, and often four distinct sets of close cutting joints. While 
it is true that this feature renders practically all the exposed stone worth- 
less, it is possible that exploration will show beds free enough from joints 
to warrant quarrying, since much of the stone, in the most favorable 
places, is unexposed. (It must be borne in mind that all the stone thus 
rendered useless for building purposes is of value as road material.) 
Eesults of tests of this rock for road material are given on p. 266. 

The statements above made apply to probably all portions of rock. The 
portion of the stone that has been termed marble is usually very fine- 
grained. The color is white with a tendency toward a blue tinge — some- 
what like the color of a white cloth that has been " blued " too much in 
washing, and is quite uniform. The stone is hard and compact and 
breaks to a sharp edge. It contains varying quantities of quartz, which 



THE CALCAREOUS ROCKS: LIMESTONES AND MARBLES. 203 

occurs as small grains scattered irregularly throughout the stone — appar- 
ently sand grains that were deposited when the limestone beds were 
themselves deposited- — as small masses of various shapes and as thin seams 
or veins that mark former joints and fractures. Sometimes there is only 
a very small amount of this quartz present, while again the rock may be 
so siliceous that it may be called a calcareous sandstone. This last con- 
dition is seen only very close to the southeast contact with the country- 
rock, which, on this side of the marble, is sandstone or quartz schist. As 
a rule, the best beds contain only a very small amount of impurity of any 
kind. 

The marble, while it is seriously injured by joints, is in much better 
condition in this respect than that portion of the stone which has been 
called limestone. As a rule, there are only two sets of joints varying from 
less than a foot to perhaps 8 feet apart. Thus, in some places, blocks of 
stone of good size may be obtained. The joints trend N\ 20° -30° E. and 
N. 50°-60° W. and the beds of stone dip 45°-50° S. 45° ± E. 

Some years ago, the State Geological Survey did considerable explora- 
tory work in the marble beds on Col. J. G-. Yancey's plantation at Wood- 
lawn with a Core drill. Several holes were put down in such a manner 
as to include a thickness of nearly a thousand feet of the stone. Kecords 
made at the time this work was done say that while much of the stone 
is rendered worthless by the jointing, some portions of it are fairly free 
from joints and will thus furnish valuable stone. 1 The cores from this 
drilling are now in the State Museum at Ealeigh and were examined 
during the preparation of this report, but they are badly broken and 
furnish little satisfactory information as to the condition of the beds 
from which they were taken. 

This stone is at present practically inaccessible, being 10 miles from a 
railroad, in a mountainous country where the country roads are in very 
poor condition. However, the South and Western Eailway has a survey 
of a proposed extension running within a mile of the most favorable out- 
crops of the marble, and it seems probable that the road will be built in 
the very near future. In fact the road is now built and trains are run- 
ning within 12 miles of the outcrops. 

MITCHELL COUNTY. 

One of the most favorable marbles in the State has recently been ex- 
posed in a cut on the South and Western Eailway, on the north bank of 
North Toe Eiver near the mouth of Sinkhole Creek, about ?>V 2 miles above 

1 J. V. Lewis, First Biennial Report of the State Geologist, 1891-1892, p. 97. 



204 



BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 



Toe Cane station. The exposure consists of a bed of very pretty coarsely 
crystalline white marble, quite similar in color and texture to the white 
marble at Tate, Gra., about 60 feet thick, interbedded with typical mica 
schist. The rock is exceptionally pure and the texture is very uniform 
■ — in fact, the stone seems to be homogeneous throughout. Also judging 
from the exposed stone and the blocks which were blasted out while mak- 
ing the cut, it is remarkably free from joints. Many large blocks were 
noticed in the embankment and very few of them showed any traces of 
joints. From one piece a block of stone, perhaps 5x8x12 feet, entirely 
free from flaws, and uniform in color and texture, could be obtained. 

The marble bed, while it may vary somewhat, has an average thickness 
of about 60 feet. It trends K 20° or 30° E. and dips about 50° S. 45° 
E. It can be traced northeastward for about a mile from the outcrop at 
the railroad, the texture, purity, and color being remarkably uniform. 




80 ft. 



Fig. 4. — Pegmatitic dike (c) cutting the Mitchell County marble (6). The country 
rock is a contorted typical mica schist (a), which at the contact with the marble Is 
quite calcareous. 



The exposure is by no means continuous, but boulders may be seen stick- 
ing out of the ground here and there. The outcrop farthest distant from 
the railroad consists of only a few fair sized boulders on the mountain side 
near a house occupied by Mr. Howell. Another occurs on the north side 
of Sinkhole Creek on land belonging to Mr. W. F. Johnson. No out- 
crops could be found on the south side of the river. 

A peculiar feature of this marble deposit, and one which detracts more 
or less from its value, is the occurrence of a large pegmatite vein in the 
midst of the marble (see Fig. 4). This vein consists of quartz and feld- 
spar, with more or less mica in places. This pegmatite apparently ex- 
tends the whole length of the marble bed and even farther, for it was 
traced over a mile beyond the last outcrop of marble. However, no indi- 
cations of it were seen at the outcrop on Mr. Johnson's land. 



THE CALCAKEOUS ROCKS : LIMESTONES AND MARBLES. #05 

The country rock is a much contorted typical mica-schist which at the 
contacts with the marble is quite calcareous. 

This stone is favorably located for quarrying, being on a mountain side 
about 100 feet above the Yalley, thus affording natural drainage and space 
for disposal of waste material. The North Toe Biver, which runs within 
a few yards of the exposure, can at very little expense be made to furnish 
ample power for operating a quarry. Also the belt is crossed by the 
South and Western Eailway, which makes connections with the Southern 
Eailway at Johnson City, Tenn., 50 miles distant, thus affording easy 
outlet for any stone that might be ready for market. 

LIMESTONE. 

SOUTHEASTERN AREA. 

In many counties of the southeastern portion of the State, especially 
Craven, Beaufort, Onslow, Duplin, Pender, New Hanover, and Bruns- 
wick, there occur deposits of more or less consolidated marls and lime- 
stone of Eocene age. 2 These are made up for the most part of calcerous 
shells and fragments of shells cemented with carbonate of lime. This 
stone is locally known as " shell rock " and in texture is very coarse, there 
being much space between the individual shells and fragments. Between 
this condition and a fairly fine-grained rock, which very closely resembles 
the coquina stone of Florida, every gradation is found. This material is 
not continuously consolidated over any large extent of territory, but 
is found in the condition of limestone only in local areas of vary- 
ing size, sometimes only a few square yards in extent, and again 
the solid beds may be continuous for several hundred yards. The rock is 
usually covered with from a few to many feet of soil and is seen out- 
cropping only in a few places along the streams. It is always soft and 
easily worked when first taken out of the ground but hardens very mater- 
ially as it remains exposed to the sunlight and air. Indeed, it is so soft 
when first taken out of the ground that it may be hewn and fashioned 
into blocks with very crude tools. Some areas of it have furnished stone 
for local use in stone walls, foundations, piers and jetties, but by far the 
vast majority of it is suitable only for burning into lime or as road metal. 
Another use to which this marl and limestone may possibly be put is the 
manufacture of cement. For this purpose it would have to be used in 
connection with clay of the requisite composition, and indeed it appears 

2 For a full discussion of the marls and shell limestones of Eastern North Carolina, 
see report of the N. C. Geol. Survey, 1852, pp. 2-112, E. Emmons, State Geologist. 

15 



206 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

from the small amount of investigation done upon the subject that in 
many localities clay suitable for such use may be found in close proximity 
to the limestone. For value as road metal, see p. 266. 

Some of the promising localities of this shell rock and marl are along 
both the Neuse and Trent rivers in the vicinity of Newbern. It is exposed 
in the banks of these streams in many places within distances of from one 
to 20 miles from Newbern. In some exposures near the city the stone 
has been quarried for local use in foundations, on the roads as macadam, 
etc. A rather pretty coarse shell rock was quarried on the Trent Eiver 
a short distance from Newbern some years ago and used in the walls and 
archways enclosing the city cemetery. The open texture of the rock gives 
this work a rustic appearance that is very attractive. 

At many places in the counties above named, shell rock very similar to 
that in Craven County has been located and in a few places, as the city 
quarry and other localities in the vicinity of Wilmington, the stone has 
been opened for local use ; also it was worked at Castle Hayne a few years 
ago as a phosphate rock. A rather promising exposure of a compact, 
stratified phase of this limestone is known to occur in the vicinity of 
Southport, in Brunswick County. At this point a bluff of the limestone, 
probably 15 feet high, is showing in the bank of a large creek, and from 
all appearances, this is probably the largest and best body of this rock in 
the State. It has not been opened, but sufficient exploratory work has 
been done to show that the deposit is of considerable value. The stream 
upon which it is located is large enough to allow the passage of boats of 
15 tons burden, thus affording water transportation for this stone in case 
it should be quarried. The following is a chemical analysis of the rock, 
furnished by Mr. E. A. Parmelee, of Wilmington, N. C, the owner of the 
property : 3 

Analysis of Limestone from Southport, N. G. 

Si0 2 12.04 

Fe 2 3 2.02 

A1 2 3 1.44 

CaO 33.56 

MgO 8.79 

Loss on ignition (includes C0 2 ) : 37.96 

Undetermined 4.19 

Total 100% 

3 Analysis by C. N. Forrest, Long Island City, New York. 



THE CALCAREOUS ROCKS I LIMESTONES AND MARBLES. 207 

PIEDMONT AND MOUNTAIN AREAS. 

In a few of the Piedmont and mountain counties of the State occasional 
areas of limestone occur. These are usually small beds of limestone inter- 
calated in the schists and gneisses. In extent they are for the most part 
narrow lenses varying from a few to 200 or 300 feet in width and from 
a few hundred yards to several miles in length. So far as known, none 
of this limestone is of such quality as to be used for building purposes 
except to supply purely local demands. But a great deal of the stone will 
burn to a good grade of lime, and for this purpose it is of considerable 
economic importance. Much of this rock, possessing as it does, a high 
cementing value and a fair resistance to wear, makes an excellent road 
metal. 

There are a number of localities in these areas where the stone appar- 
ently occurs in sufficient quantity to be of economic value as a source of 
lime. In Buncombe County, about 2 miles north of Fleteher, Henderson 
County, a station on the Southern 'Railway, a limestone quarry has re- 
cently been opened by the Blue Ridge Lime Company. 4 It is on the same 
limestone strata as the old Lance lime quarry, but 600 to 700 feet distant 
from this on what is known as the Westfeldt property. The Company 
have erected two kilns which have a capacity of 700 bushels per day 
(A, Plate XXVIII). The quarry and kilns are connected by a tramway 
with the railroad at Fletcher. The limestone is of a peculiarly fine- 
grained structure with a very smooth touch. Analyses of this stone by 
Mr. D. K. Pope of the United States Assay Office at Charlotte gave the 
following results : 

Analyses of Limestone from Fletcher, N. C. 

I. II. 
Per Cent. Per Cent. 

Silica 1.40 1.70 

Alumina and ferric oxide 58 .58 

Lime 53.32 53:38 

Magnesia 1.62 1.32 

Carbonic acid 43.66 43.39 

Total 100.58 100.37 

There are little or no impurities in the limestone, and the calcium 
carbonate constitutes 95.32 per cent of the rock. A test was made also 
by Mr. Pope of this limestone by burning Sample I at a strong red heat 
for two hours, at the end of which time 95.74 per cent of the theoretical 

4 J. H. Pratt, N. C. Geolog. Survey, Economic Paper, No. 9, p. 76, 1905. 



208 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

amount of lime was obtained. The stone burned easily and made a pure 
white lime- In Sample II, which was heated for two hours at a strong 
red heat, there was 90.3 per cent of the stone converted into lime, which 
was also a very white lime and gave no difficulty in burning. Another 
hour's heating would have converted practically all of the rock into lime. 

In B of Plate XXVIII is shown a chimney that was built in the year 
1846 by Mr. N. J. Lance from mortar made from air slacked lime ob- 
tained by burning limestone from the Lance quarry. The chimney stands 
as solid and erect to-day as when first built and the mortar is in almost 
perfect condition. 

In Henderson County quite a large body of limestone occurs 7 to 10 
miles west of Hendersonville, the county-seat, in the vicinity of Boilston. 
The limestone outcrops at intervals from about 3 to 5 miles northeast of 
Boilston to some distance above Brevard, the county-seat of Transylvania 
County. It is capped in many places by a schistose rock and is dipping 
approximately 40° S. E. On the land of Mr. J. F. Woodfin, about f of 
a mile a little east of south of the Boilston gold mine, limestone has been 
worked for a little over 200 feet along the strike. The limestone appar- 
ently contains very little grit and is of a bluish tinge known locally as 
"blue limestone." Considerable of this limestone has been burned to 
lime, some of which has been used for fertilizing purposes. On the W. B. 
Allison farm, three-eighths of a mile due west of the Woodfin quarry the 
limestone is whiter in color and is known locally as " white limestone " 
to distinguish it from the " blue limestone " of the Woodfin quarry. A 
similar quarry has been opened on Bryson Ezell's farm 3 miles northeast 
of Allison's. Considerable of the lime burned from this limestone has 
been used for building purposes. 

In Transylvania County kilns for burning limestone have been erected 
by W. O. and Joseph Miller, George Young, and Joshua Owen near Bre- 
vard. Most of the lime burned at these kilns has been used for fertiliz- 
ing purposes. An outcrop of a limestone, which is more or less siliceous, 
forms a ridge known as Limestone Eidge on Bear Wallow Creek about 
^ of a mile above its junction with Toxaway River. The limestone out- 
crops prominently in the stream and on both sides in ridges that rise 
about 150 feet above the creek. Although this limestone is somewhat 
siliceous, it has for a number of years been quarried and burned, the lime 
being used for both building and fertilizing purposes. 

In Macon County, near the headwaters of Ellijay Creek, near Cullo- 
whee Gap, limestone has been burned to lime for building and fertilizing 
purposes on the property of John Bryson. About one-half mile west of the 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXVHI 




A. LIME KILNS OF THE BLUE RIDGE LIME COMPANY AT THE LANCE QUARRY, 2 MILES NORTH OF 

FLETCHER, N. C. 




B. CHIMNEY BUILT IN 1846 WITH MORTAR MADE FROM LIME OBTAINED FROM THE LIMESTONE OF 

THE LANCE QUARRY. 



THE CALCAREOUS ROCKS! LIMESTONES AND MARBLES. 209 

Gap is the Haskett lime quarry that was worked quite extensively some 
years ago. 

In Gaston County the most promising deposits are in the vicinity of 
Bessemer City and Kings Mountain. The stone at this point is said to 
make a first-class lime and considerable has been burned and used locally 
for building purposes. A similar limestone is found in a number of 
places in Lincoln and Catawba counties. 

At Hot Springs, in Madison County, is one of the largest and best 
known limestone deposits in Western North Carolina. The rock oc- 
curs in inexhaustible quantities and may be seen forming a high bluff on 
the French Broad Eiver about one mile below Hot Springs. The rock 
is too badly shattered and is not of proper quality for use as a building 
stone, but it has been used to some extent for burning into lime and is 
said to be well adapted for this purpose and to produce a good quality of 
lime. It also possesses a reasonably high cementing value and a fair re- 
sistance to wear, and consequently is well suited for use as road metal. 
For results of tests of this stone for road building purposes see page 266. 
In other places in this County small deposits of limestone occur as narrow 
lenses in the schists and gneisses. One of the largest of these is found on 
Little Laurel Creek just south of Allen Stand. The stone at this point 
is apparently a fairly pure limestone and will undoubtedly burn to an 
excellent quality of lime. 

On the north fork of the Catawba Eiver, in McDowell County, about 
10 miles north of Marion, limestone occurs in large quantities and may 
be traced by means of disconnected outcrops from the plantation of 
Colonel J. G. Yancey (Woodlawn) to the head of North Cove, a distance 
of perhaps 15 miles. In some places, especially near Woodlawn, the stone 
is a fair grade of marble and offers considerable promise as a building 
stone (see page 202). For the most part, however, it is simply a 
badly shattered limestone or dolomite and can be used only as road metal 
or in the manufacture of lime. For results of tests of this stone for road 
building purposes see page 266. 

Near Germantown in Stokes County a bed of limestone 40 to 50 feet 
thick occurs. This deposit was known and worked to supply stone for 
local use and for burning into lime prior to fhe Civil War. It was then 
known as " Bole jack quarry." 5 

5 Report on the Soils and Agriculture of the Lower Counties, and the Coal Fields of 
Rockingham, Stokes, Chatham, and Moore Counties, Report North Carolina Geological 
Survey, 1852, page 180, E. Emmons, State Geologist. 



CHAPTER Y. 

THE SERPENTINES AND VERDANTIQUE MARBLES. 

The rocks grouped under this head are invariably of secondary origin. 
They originate only through processes of chemical changes, or alteration, 
such as are all comprehended under the general name of metasomatosis. 
The meaning of this word can be best explained as a process of indefinite 
substitution and replacement, that is to say, the original rock has been 
modified through the carrying away, by solution, of a portion of the 
original constituents and their replacement by others. 

The serpentinous rocks of North Carolina have resulted mainly from 
the alteration of basic, igneous rocks of the nature of peridotites. These 
rocks are composed mainly of the silicate minerul olivine, with, it may be, 
enstatite, together with magnetite and chromic iron. Otherwise ex- 
pressed, they are composed mainly of silica and magnesia with smaller 
amounts of alumina, iron and lime. The process of alteration has re- 
sulted, as a rule, in a loss of a portion of the original silica, a portion or 
all of the lime, where such existed, presumably part of the magnesia also, 
and an assumption of water, the processes being accompanied by an oxi- 
dation of the combined iron. In cases where the original rocks con- 
tained lime-bearing silicates, the lime set free has combined with car- 
bonic acid to form carbonate of lime, or calcite, and been either carried 
away in solution, or re-crystallized as veins of spar. The iron oxides and 
sometimes ca? bonates of magnesia and iron also sometimes separate oat in 
the same way, thus diversifying, and sometimes adding to the beauty of 
the stone. 1 

The fact that the process of alteration, which gives rise to those serpen- 
tinous rocks is one of indefinite substitution and replacement, added to 
the differences in composition of the rocks from which such may have 
been derived, causes a considerable difference in composition among the 
various rocks to which the name serpentine is commonly applied. A pure 
serpentine consists of silica, magnesia and water in the following pro- 
portions : 

1 For full description of Peridotites and Serpentines see Vol. I, N. C. Geol. Survey, 
" Corundum and Peridotites of Western North Carolina," J. H. Pratt and J. V. Lewis. 



THE SERPENTINES AND VERDANTIQUE MARBLES. &11 

Theoretical Composition of Serpentine. 

Per cent. 

Silica, Si0 2 44.1 

Magnesia, MgO 43.0 

Water, H 2 12.9 

Total 100.0 

As a matter of fact, however, nearly all serpentines are impure, showing 
a quite variable composition, the chief variations being in the percentage 
amounts of iron and alumina. 

The normal color of the serpentines is some shade of green or yellow, 
though often diversified by red, brown, white or even black shades. The 
prevailing, though somewhat diversified greenish hues, are recognized in 
the name, which is derived from the Latin word serpeniinus meaning 
serpent-like. 

STRUCTURE. 

In structure the serpentines are almost universally brecciated, though 
it may be so coarsely so that slabs and blocks of considerable size of uni- 
formly even texture are obtainable. In cases where the original serpen- 
tinous fragments have been re-cemented by the deposition of the lime or 
magnesian carbonates along the line of fracture, a beautiful marble may 
result as is well exemplified in the celebrated Yerde de Genova, and 
Verde de Prato marble of Italy. Ordinarily the serpentines are very 
compact and without evident crystalline structure, and have a somewhat 
greasy lustre and feel. The impure varieties are, however, often more or 
less porous. 

WEATHERING QUALITIES. 

Although composed of material so largely insoluble, the serpentines are 
not invariably of an enduring nature. This is due mainly to in- 
equalities in texture and composition. The verdantique marbles, when 
exposed early, lose their polish and not infrequently open up along the 
numerous seams and joints by which even the best varieties are traversed, 
and become quite unsightly. Such should be used, therefore, only where 
protected from atmospheric action. The rough forms, used for general 
building are, as a rule, very durable, though even here inequalities in tex- 
ture may bring about disastrous results. The stones are almost uni- 
versally badly jointed, and if blocks of more than very moderate dimen- 
sions are used, defects are likely to develop on short exposure. Carefully 
selected, and used in rock faced or tool dressed work, the stone forms an 
admirable building material. 



212 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

USES. 

The uses to which the serpentines are put depend very largely on their 
colors and the possibility of obtaining blocks sufficiently sound to be 
sawed into slabs or turned into columns. The finer grades, often diver- 
sified by veins and dashes of white or gray, are used for interior decora- 
tion, under the name of verdantique marbles. Others, which will not 
yield slabs of such size as to make them desirable for this purpose are 
utilized in making small objects of ornamentation, such as bases for 
statues, vases, etc. The stone is sufficiently soft to be turned on a lathe, 
and hence, when the colors are good, is admirably adapted for such pur- 
poses. The great drawback to the use of the stone for wainscoting and 
like forms of decoration lies in its dark and cold color. In well lighted, 
sunny rooms, this objection is largely done away with and the effects pro- 
duced through its use are often admirable. The rough, impure forms, 
such as will not polish, are used in many instances for general structural 
purposes. Many private and public buildings in the cities of Baltimore, 
Philadelphia, and Washington are constructed from such material brought 
mainly from Chester County, Pennsylvania, and adjacent portions of 
Maryland. 

GEOGRAPHICAL DISTRIBUTION. 

The distribution of the available serpentine in the State is limited 
largely to the counties of Buncombe, Caldwell, Madison, Watauga, Yan- 
cey, Wake, and Wilkes. It occurs in small quantities in nearly all the 
mountain counties, 2 but as a rule the deposits are small and the color not 
suitable for ornamental purposes. In all of these localities the stone 
occurs in the form of dikes which are usually quite narrow, though they 
may extend for long distances. The material thus far found is almost 
invariably of a dull green to dark green color, though sometimes light 
yellowish green. It always contains an abundant sprinkling of dark 
granules and veinlets of chromic iron ore, which, however, so far as 
observed, do not injure the stone for purposes of general construction. 
No serpentine suitable for use as a high grade decorative stone has yet 
been found in quantity within the State limits. 

BUNCOMBE COUNTY. 

The serpentine dikes of this County are confined to the western portion 
of the County and are found as small, disconnected, lenticular outcrops 
extending irregularly from the vicinity of Canton northeastward to the 

2 Corundum and Peridotites of Western North Carolina, J. H. Pratt and J. V. Lewis, 
Vol. I, N. C. Geol. Survey. See " Serpentine." 



THE SERPENTINE AND VERDANTIQUE MARBLES. 213 

French Broad Eiver near Alexander, and from thence northeastward to 
near Stockville. The outcrops are always small, seldom exceeding 30 
feet in width and a few hundred yards in length. The color of the stone 
varies from a very dark green to a light yellowish — or grayish green, the 
dark green apparently being the prevailing color. All the outcrops are 
at present practically inaccessible, being in a mountainous region with few 
wagon roads, and from one to 10 or more miles from a railroad. A few 
of the most promising are located as follows : 

On a farm belonging to Mr. W. L. Foster about 2y 2 miles west from 
Olivette station on the Southern Kailway, is probably the most favorable 
exposure of serpentine in the County. The dike, which has a width of 
from 16 to 20 feet, is exposed near the top of a small hill and in such a 
position that it could be opened with no very great expense. The stone 
varies in color from a dark green to a light yellowish green, the latter 
being, as far as could be determined, from the small exposure, the pre- 
vailing color. The stone near the surface is badly weathered and dis- 
colored, but a small amount of excavating, which was done some years 
ago, shows that at a depth of 10 or 15 feet it is hard and fresh. 

Another exposure very much like the one just described occurs a short 
distance further southwest on land belonging to Mr. W. E. Pounder. The 
dike at this point is considerably wider than the outcrop on Mr. Foster's 
land, being about 40 feet. The color is not quite so desirable as the other 
stone, being for the most part of a light-gray or yellowish-green. It is 
also apparently very deeply weathered and thus not quite so favorable a 
stone. 

One and a fourth miles above Alexander a 15 foot dike of dark green 
serpentine is exposed in a cut on the Southern Eailway. The stone con- 
tains a considerable amount of chromic iron ore in the form of small 
veins and granules and is apparently so badly jointed that only small 
blocks could be obtained. Another outcrop of this same dike occurs about 
114 miles northeast of this place. The exposure is best seen in the bed 
of Eeems Creek about % mile from its junction with the French Broad 
Eiver. The stone at this place is of a beautiful dark green color — varying 
from a very dark green to a deep clear yellowish-green. It also appears 
to be more massive than the outcrops just described, and it is not impos- 
sible that some marketable serpentine may be obtained at this place. 

Another exposure of similar stone occurs about one mile northwest of 
Weaverville, 3 and extending in a series of disconnected outcrops the ser- 
pentine may be traced northeastward into Yancey County. 

3 Corundum and Peridotites of Western North Carolina, J. H. Pratt and J. V. Lewis, 
Vol. I, N. C. Geol. Survey, pp. 105-106. 



214 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

WILKES COUNTY. 

One of the most favorable exposures of serpentine in the State occurs 
on Eeddies Kiver, about iy 2 miles northwest of North Wilkesboro. 
Messrs. Pratt and Lewis in their report on the Corundum and Peri- 
dotites of Western North Carolina make the following statements re- 
garding the serpentine deposit: 4 

" The deposit (asbestos) near North Wilkesboro is within three-fourths 
of a mile of the railroad and occurs in a serpentine formation that is from 
75 to about 200 feet in thickness and can be traced in a general N.W.- 
S.E. direction for nearly 600 yards. The deposit has been worked by 
means of an open cut 100 feet long, which was made on the land of Mr. 
J. B. Church. The cut varies in depth from 1 to 35 feet and near the 
surface the serpentine encountered was much decomposed and altered, 
but at lower depths a compact, dark green rock was found. This harder 
rock is similar to a bold outcrop of serpentine that occurs on a low hill 
about 300 yards a little east of south of this cut on land belonging to Mr. 
G-. W. Hinshaw, of Winston, N. C. A similar outcrop of serpentine was 
observed on the summit of a hill 200 yards nearly north of the cut. In 
nearly all of this serpentine small seams of chrysotile asbestos were ob- 
served that varied in thickness from a quarter of an inch to nearly 2 
inches, the thicker ones having been found in the bottom of the cut. 
These seams run at all angles through the rock and as the unaltered ser- 
pentine was encountered, the quality of the asbestos became better/' 

On another page 5 in the same report this deposit is spoken of as follows : 

" Another deposit (serpentine) that is worthy of investigation is the 
one in which asbestos occurs, near North Wilkesboro, Wilkes County. At 
the bottom of the cut made in prospecting for asbestos, the serpentine 
obtained was of good color (dark green), hard and compact and took a 
good polish. It is within three-fourths of a mile from the Southern Bail- 
way and water-power is available for sawing the stone." 

MADISON COUNTY. 

A series of small, disconnected, lenticular outcrops of serpentine ex- 
tends across this County from near Boyd Cap northeastward to the Wal- 
nut Mountains. They cross the French Broad Eiver near the mouth of 
Little Pine Creek about 2 miles west of Marshall. Near this point many 
small outcrops of serpentine, soapstone and dunite occur, but no work 
has been done at any of them, and since they are all in a mountainous 

4 Corundum and Peridotites of Western North Carolina, J. H. Pratt and J. V. Lewis, 
Vol. I, N. C. Geol. Survey, p. 394. 
5 Loct. cit, p. 399. 



THE SERPENTINE AND VERDANTIQUE MARBLES. 215 

region, with very poor wagon roads and several miles from the railroad, 
they are at present wholly inaccessible. 

Other deposits, often quite large and of dark-green to yellowish-green 
color, occur on Paint Fork of Ivy Eiver in the northeastern portion of 
the County. 6 The color of the stone and the nature and size of a few of 
these outcrops, seem to indicate that exploratory work might show up 
serpentine suitable for building and decorative purposes. The outcrops 
are all far removed from the railroad and are at present inaccessible. 

Other deposits similar to those just mentioned occur on Bald Creek in 
Yancey County. Also a large deposit of very dark green serpentine 
occurs near Cook Gap in Watauga County. These exposures are all far 
from means of transportation, and no exploratory work has been done at 
any of them. Consequently, they can at present be mentioned only as 
possible sources of serpentine. 

WAKE COUNTY. 

The serpentine of this County occurs along Barton Creek about 14 or 
15 miles northwest of Ealeigh. The rock is in the form of a dike of 
varying width, averaging possibly 250 feet. The dike in some places has 
been changed into soapstone and large masses of radiating green amphi- 
bole, probably actinolite, but for the most part the alteration has been 
into a dark to light yellowish-green serpentine. It contains many vein- 
lets and granules of chromic iron ore, which vary greatly in amount 
present, sometimes occurring in great abundance and again rather spar- 
ingly. The stone, as is always the case with serpentine, is badly broken 
and jointed, but not to an extent that would ])revent the quarrying of 
blocks of sufficient size for building purposes. 

The exposures were found to be almost continuous, the width varying 
greatly from place to place, for a distance of nearly 2 miles. The texture 
and general character of the stone, except the color, which varies from 
dark to yellowish-green, appears to be fairly uniform throughout this 
entire distance. It does not, however, so far as observed, possess those 
qualities which are demanded of a high-grade decorative stone, the color 
generally being too dark and uninteresting for such purposes. But it is 
unquestionably of such character as to be of some value as a general 
building stone. 

The stone occurs on the farms of Dr. A. J. J. Penny, Mr. Jesse Adams, 
and Mr. Joseph Tadlock respectively, and in many places on these farms, 
the exposures are of such a nature that quarries could be opened with little 
difficulty. 

6 Corundum and Peridotites of Western North Carolina, J. H. Pratt and J. V. Lewis, 
Vol. I, N. C. Geol. Survey, pp. 53, 399. 



CHAPTER VI. 

THE SANDSTONES AND QUAKTZITES. 



VARIETIES. 

Under this head are grouped a widely varying series of rocks, having 
only in common the one property of being composed of more or less con- 
solidated sands. They are made up of siliceous fragments derived from 
the disintegration of older crystalline rocks which have been rearranged 
through the mechanical action of water. The material by which the in- 
dividual particles of a sandstone are bound together is, as a rule, of a 
calcareous, ferruginous (iron oxides), or siliceous nature, though some- 
times argillaceous (clayey). The substance, whichever it may be, has 
been deposited between the granules by percolating water or during the 
process of original sedimentation and forms a natural cement. Upon 
the character of this cement is dependent, quite largely, the color of the 
stone and its working and lasting qualities, as will be noted later. Stones 
containing any considerable amount of ferruginous cement are nearly 
always of a yellow, brown, or red color. Several varieties of sandstone 
are popularly recognized, the distinctions being founded upon color or 
working qualities. Thus the name brownsione is applied to a sandstone 
containing so large a proportion of a ferruginous cement as to give it a 
brown or red color. The term freestone is given to any sand or limestone 
of sufficient uniformity of texture to work freely in any direction. The 
terms calcareous, ferruginous, siliceous, or argillaceous are often applied 
to sandstones in which these constituents play the role of cementing 
materials. Siliceous sandstones, which have undergone metamorphism 
like those near Hot Springs in Madison Count} 7 , are known as quartzites. 
Many sandstones, owing to their laminated or thinly bedded structure, 
can be split out from the quarry only in the form of comparatively thin 
slabs, too thin for building purposes, but eminently suited for flagging. 
Such are often called flagstone, though the name is equally applicable to 
any stone thus used. 

From a geological standpoint, the sandstones are known as Triassic, 
Carboniferous, or Silurian, etc., according to the period during which 
they were formed. According to the size and shape of their constituent 



THE SANDSTONES AND QUARTZITES. 217 

particles, they are known as sandstones proper, or, if the grains are large 
and rounded like a consolidated gravel, as conglomerate. When these 
large granules are angular instead of rounded, the stone is known as a 
breccia. 

STRUCTURE. 

The internal structure of the sandstones, as may readily be imagined, 
is quite variable. In some the particles are angular and in others they 
are rounded (see Fig. B, PI. XXVII) ; at times the particles are of uni- 
form size, or, again, they may be widely variable; at times closely com- 
pacted, or again, with a varying amount of interstitial space to be filled 
by cement. Most sandstones possess a more or less evidently laminated, 
banded, or bedded structure, due to the fact that they were laid down as 
sands or gravels on sea bottoms though this lamination is not always 
sufficiently pronounced to be visible in small blocks. 

WEATHERING QUALITIES. 

From the standpoint of durability (the power to resist atmospheric 
agencies), sandstones are the most variable of natural building materials, 
and with no class of stone is more judgment necessary in making selec- 
tion than here. Some are capable of resisting, unharmed, for many years 
the most severe attacks of heat and frost; other succumb so readily as to 
be practically worthless. This wide variation is due, as may readily be 
imagined, to the equally wide variation in structure and composition. 
Sandstones which will absorb more than five per cent of water are liable 
to injury from freezing ; hence the ratio-of-absorption test is an important 
one with this class of rocks. Moreover, many sandstones have a dis- 
tinctly laminated structure. Such, when exposed in the walls of a 
building, particularly when placed on edge, are more likely to undergo 
exfoliation than those more massive. Sandstones in which the cementing 
material is calcareous are susceptible to the action of atmospheric waters, 
whereby the cement is removed, and the stone slowly disintegrates. Of 
all cementing materials the calcareous matter is most susceptible and the 
siliceous the least so, the ferruginous standing intermediate. Other 
things being equal, a purely siliceous sandstone (the siliceous granules 
being held together by a siliceous cement) is the most durable, though, 
unfortunately, the stones of this class are, as a rule, less desirable on 
account of color than are the ferruginous varieties. Many sandstones, 
and particularly the lighter varieties, such as are quarried from below the 
level of the ground water, contain iron pyrites, which oxidizes on ex- 



218 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

posure, staining the rock either locally with unsightly blotches, or as 
causing it to take on a more uniform rust or cream tinted hue. Mechani- 
cal disintegration, either through a removal of the cementing matter or 
through the freezing of absorbed water, is the main cause of failure so 
common among stones of this class. The quartzites are, as a rule, less 
absorptive than are the sandstones and less affected by chemical agencies. 
Unfortunately, their poor colors and working qualities are something of 
a drawback to their very extensive use. 

QUARRYING AND WORKING. 

Sandstones occur in beds of varying thickness, once nearly horizontal, 
though they may now be inclined at varying angles. They are, as a rule, 
sufficiently soft to be quarried by the aid of channelling machines where 
the position of the beds will permit their use, and can be sawed with the 
ordinary reciprocating gang or diamond-toothed circular saws. They 
can also be worked with steam planers and tool-dressed in any desired 
form. Owing to their laminated structure, they split most readily along 
the plane of lamination, but in all the better qualities can be cut readily 
at right angles to this plane. 

USES. 

The sandstones are used almost wholly for exterior work, as in walls 
and steps of buildings, being, on account of color and texture, or lack of 
susceptibility to polish, quite unsuited for interior decoration, or for other 
than the more massive forms of monumental work. Owing to the ready 
working qualities of the freestone varieties, they are often elaborately 
carved, though it must be confessed that only too frequently the ability 
of the stone to withstand the rigors of our climate has been disregarded, 
the work crumbling to a condition quite the reverse of ornamental within 
a comparatively brief period. The variety of colors, the possibility of 
utilizing them in almost any sort of finish (from rock-dressed, through 
tool-dressed to sawed or sanded surfaces), and the cheapness with which 
such can be quarried and worked have long made the sandstones, as a 
whole, favorite materials for construction with architect as well as with 
builder. 

GEOGRAPHICAL DISTRIBUTION. 

The exploitation of the sandstones in the State is limited wholly to 
the Triassic beds, the distribution of which is shown in the accompanying 
map. These rocks, it should be noted, are the equivalent, geologically 
and lithologically, of the celebrated brownstones so generally used in 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXIX 



Tayiorsville 1 

JR. a. q 




MAP OF CENTRAL PORTION OF NORTH CAROLINA SHOWING DISTRIBUTION OF THE TRIASSIC 

SANDSTONE. 



THE SANDSTONES AND QUARTZITES. 219 

New York and which have been quarried for many years in the Con- 
necticut Valley, northern New Jersey, in Pennslyvania, in Maryland at 
Seneca Creek, and at Manassas in Virginia. The colors vary somewhat 
throughout the belt, but are as a rule, of a prevailing red-brown hue, 
rarely grayish brown (see PL XXIX). 

As will be noted, the chief drawback to successful quarry development 
has, thus far, been the abundant jointing of the beds, whereby the stone 
is broken into polygonal blocks of comparatively small size. A lack of 
uniformity in color of the various beds has also proved a detriment. In 
the descriptions which follow, the quarries and outcrops are taken up 
and discussed systematically, beginning with the southernmost. 

ANSON COUNTY. 

WADESBORO AREA. 

The Triassic sandstone extends across this County from the southwest 
to the northeast in a strip or belt of irregular boundaries, varying in 
width from 8 to 15 miles. The stone, for the most part, is covered by 
soil, but in many places, along streams and in railway cuts, good ex- 
posures are seen. The beds throughout the area are cut by three systems 
of joints, from a few inches to 25 or 50 feet apart, and trending usually 
from N. 30° to 60° W. and 1ST. 60° to 30° E., and N. and S., those first 
mentioned seemingly being of greatest importance. 

Cutting the sandstones always in the direction of a set of joints are a 
great many diabase dikes, varying in width from a few inches to several 
hundred feet. These dikes are nearly always vertical. A section across 
the sandstone beds from about a mile west of Lilesville, along the Sea- 
board Air. Line Kailway to near Polkton, a distance of perhaps 15 miles, 
shows over fifty of these dikes. And since the stone is not exposed for 
more than half the distance, it is possible that there may be in reality 
twice this number. 1 

No systematic quarrying has been done in this County since 1890. 
However, one or two small openings are worked now and then to supply 
stone for local demand. Some of the most prominent openings and out- 
crops are as follows: 

THE OLD L1NEHAN QUARRY. 

This opening is on the Jesse Edwards estate about l 1 /^ miles northwest 
of Wadesboro and only a short distance from the Seaboard Air Line Rail- 
way, with which it was once connected by a side-track. The opening is 

iBull. No. 85, U. S. Geol. Survey, p. 95. 



220 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

in the northwest slope of a small hill and is drained by a small stream. 
The beds vary in thickness from 5 or 6 inches to as many feet and dip 
about 20° S. 35° E. The upper beds are variable in color and texture 
and are badly decomposed and worthless. Only one bed of any promise 
is exposed. It is the lowest and is about 6 feet in thickness. This bed 
is of a light red-brown color, uniformly fine-grained, but in some 
places contains small clay holes or " pockets." Its upper part shows 
a distinct tendency toward a shaly texture. This bed, as all the others, 
is broken by two prominent sets of joints — N. 30° W. and N". 60° E. 
Those of the first set are from 2 to 6 feet apart and of the second from 
2 to 50 feet. 

The fact that stripping now amounts to 12 or 15 feet, and must 
steadily increase as the work advances probably accounts for the quarry's 
being abandoned. 

THE W. A. POLK QUARRY (FORMERLY THE WADESBORO BROWNSTONE COMPANY'S 

QUARRY) . 

This quarry, which has been abandoned for several years, is the one 
that furnished the " Waclesboro Brownstone," used quite extensively as 
a building stone in 1889 and 1890. The opening is about 1^ miles north- 
west of Wadesboro and about one-fourth mile west of the opening just 
described. 

Here, as in the old Linehan opening, there are two sets of joints, N". 
60° E. and N". 30° W. The first indicated is the most prominent, the 
joints being from 1 to 7 feet apart. The others are from 5 to 25 feet. 
The beds dip approximately 25° S. 15° E. 

The following vertical section of the stone exposed in the quarry face 
will give an idea of the succession of beds in this quarry. 
1. a 15" Chocolate-brown, fine-grained. 

Light-brown, almost a gray, fine-grained. 

Red-brown, fine-grained. 

Dark or chocolate-brown, quite similar to " a." 

Light brown or gray, similar to " b." 

This bed is quite uniform in texture throughout. 

Badly decomposed, red-shaly material. 

Light brown, almost gray, similar to " l.b." 

Badly decomposed, red-shaly material. 

Light-brown, almost a gray. 

Badly decomposed, red-shaly material. 

Reddish-brown in color, with only a slight variation in 

texture. Clay pockets. 
Badly decomposed, shaly material. 

Light chocolate-brown in color, quite uniform, but vary- 
ing considerably in texture. The lower 12 inches of 
this bed are very coarse, almost a fine conglomerate. 





b 8" 




c 8" 




d 24" 




e 10" 


2. 


12" 


3. 


18" 


4. 


8" 


5. 


b0" 


6. 


36" 


7. 


48" 


8. 


12" 


y. 


72" 



THE SANDSTONES AND QUARTZITES. 221 

Beds 5, 7 and 9 are the only workable beds in the quarry. 

From the above section it may be seen that this quarry has furnished 
stone of two colors — a red-brown and a light chocolate-brown. That 
of the last color is somewhat coarser in grain and freer from impurities 
than the red-brown stone, and is the bed that furnished the most de- 
sirable material. Stone from this quarry was used in the post office and 
Federal court buildings at Wilmington, Asheville, and Statesville; the 
Y. M. C. A. buildings in Charlotte and Atlanta, and in the Garrett 
school building in Baltimore (see PI. XXX, B). 

This stone consists of angular and sub-angular fragments of quartz 
and feldspar, biotite, much of which is altered to chlorite, cemented 
together with iron oxide, probably limonite. The quartz grains are clear 
when separated from the film or coating of iron oxide. 

The chemical composition of the stone, as given by Dr. Merrill, 2 is 
as follows: 

Analysis of sandstone from Polk Quarry, waaesooro, N. G. 

Per cent. 

Silica 69.28 

Alumina and iron oxides 13.84 

Magnesia .02 

Potash and soda 6.43 

FRANK HAMMOND'S QUARRY. 

This consists of two small openings a short distance northeast of Eocky 
Ford Church on the White Store road, 2 miles southwest of Wadesboro. 
The openings are in the sides of two small hills on opposite sides of a 
small ravine. 

The beds in each opening are from 1 to 4 feet thick and dip from 
15 to 20 degrees S. 35° E. Joints in each opening are very prominent 
and quite close. They are of two sets of equal importance, trending 
N. 35° E. and N. 40° W. respectively, and varying from 3 to 4 inches 
to as many feet apart — usually about 2 feet. The beds vary in color 
from a reddish-brown to a light chocolate. The rock is uniformly 
medium fine-grained, and is free from clay partings and "pockets" 
and other defects. The stripping now amounts to from 6 to 10 feet and 
will increase since development must proceed in direction of the dip. 

Along the east bank of Gould's Fork, 3 miles northwest of Wadesboro 
and about 200 yards northeast of where the Wadesboro- Ansonville road 
crosses the creek, is quite an extensive outcrop of light tan or buff colored 

2 Stones for Building and Decoration, Geo. P. Merrill, 2d Ed., p. 472. 
16 



222 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

sandstone. This bed of stone has a thickness of from 6 to 7 feet and is 
exposed in the upper part of a steep slope along the creek for abont one- 
qnarter of a mile. The stone is apparently fairly uniform in color, but it 
varies in texture from fine-grained compact rock to coarse, more or less 
open-grained material — almost fine conglomerate. These coarse-grained 
areas, though not extensive, are distributed rather irregularly through the 
stone. 

Joints are quite numerous, though not so close as to prevent the get- 
ting out of blocks of stone of almost any dimensions desired. They cut 
the beds as in previous instances N. 60° W., N". 30° E., and north and 
south. Their importance is in the order named, The beds are nearly 
horizontal, dipping very slightly southeast. 

Stripping would be slight — from 2 to 4 feet — and, since the outcrop 
has so steep a slope — almost vertical in some places — a large quarry face 
could be easily opened. 

W. PAESONS' QUAKRY. 

A small opening has been made about one-half a mile northwest of 
Wadesboro on a tract of land belonging to Wm. Parsons. Only one bed of 
workable stone has here been exposed. The bed is 7 or 8 feet thick, is 
covered by from 4 to 8 feet of soil and worthless rock, and dips about 15° 
S. 10° E. The stone is of medium fineness of grain, of a light chocolate 
color, of a slight reddish tinge, and is remarkably uniform in both texture 
and color. It is cut by two sets of joints of equal importance, trending 
N". 60° W. and 1ST. 30° E. and from 2 to 15 feet apart— usually from 4 
to 8 feet. This bed is unusually free from clay holes and other imper- 
fections. 

The opening is in the northwest slope of a small hill and work is 
advancing in the direction of the dip, thus causing the stripping to 
gradually increase in amount. The results of pressure tests on stone 
from this quarry are given on p. 236. 

I. H. horton's quarry. 
About one-half mile south of the above described opening is another be- 
longing to I. H. Horton. The opening has been made near the top of a 
small hill. Only one bed, about 6 or 8 feet thick, fine-grained and of a 
reddish-brown color, of workable stone has been exposed. This bed is 
neither uniform in color nor texture, is cut by two sets of joints, trending 
1ST. 60° W. and K 30° E., respectively, and from 2 to 15 feet apart. It 
dips about 15° S. 15° E., and contains many irregular "clay pockets." 
Here also work in quarrying would advance in the direction of the dip, 
and the stripping would increase very rapidly. 



THE SANDSTONES AND QUARTZITES. 223 

There are a few more small openings in the vicinity of Waclesboro 
which have been worked as prospects and in some instances to supply 
stone for local purposes. There are also many natural exposures along 
streams, but the stone does not vary in any important characteristic 
from that of the openings and outcrops described. In fact, those de- 
scribed appear from the character of the stone or location with respect 
to facilities for transportation, to be the most important sandstones in 
Anson County. 

MOORE COUNTY. 

The Triassic formation extends across the County from southwest 
to the northeast. The belt varies in width from 5 to 18 miles and has 
a rather irregular outline. As in Anson County, the stone is quite 
closely jointed, joints having the same general trend as in that County. 
It is also cut by a great many trap (diabase) dikes. These dikes, while 
not quite so numerous as those of Anson County, are, as a rule, larger. 
They always follow one of the prominent sets of joints, the majority 
probably following the northwest set, and almost invariably cut the beds 
of sandstone at right angles to the bedding planes. 

Considerable quarrying was at one time (in 1889-90) carried on in 

the northeastern part of the County, in the vicinity of Sanford. A great 

many places were prospected at that time and several quarries were 

opened, but in each case they were worked only a short time, and to-day 

a small quarry near Sanford is the only brownstone quarry in operation 

in the State. 

i 

CARTHAGE AREA. 

Some of the most promising building stone in the whole Triassic 
formation of the State occurs near Carthage. No openings have, how- 
ever, been made in this part of the County, and the observations upon 
which the following statements are based were made on natural out- 
crops. 

The stone seems to be, as a rule, more heavily bedded than in other 
parts of the Triassic area. The beds vary in thickness from 1 to 10 feet 
and apparently average from 3 to 8. The color in the different beds 
varies from a distinctly red-brown to purplish-brown. The last is the 
prevailing color. The color of each bed is, for the most part, fairly 
uniform. The texture, while it varies from quite fine-grained to coarse 
conglomerate, is, as a rule, remarkably uniformly medium grained. The 
dip of the beds is from 5° to 15°, generally about 10°, in a southeast 



224 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

direction. The jointing, while it has the same general directions, about 
northeast and northwest, is not quite so close as in other parts of the 
formation. 

Details regarding some of the promising outcrops are as follows : 

About three-quarters of a mile west of Carthage, on land belonging to 
A. H. McNeill, exposed in the banks and bed of a small stream, are several 
beds of stone, generally of one or two prevailing colors — a distinctly 
reddish-brown and a kind of gray chocolate-brown, the latter color being 
by far the prevailing shade. The various beds appear to differ slightly 
among themselves, but each bed, for the most part, seems to be quite 
uniform. There is some variation in texture or grain, but, as a rule, it 
is of medium fineness. 

The beds dip slightly, about 5° or 6° southeast, and are from 2 to 8 
feet thick. They are cut at right" angles to the bedding planes by two 
sets of joints, trending 1ST. 45° E. and N. 50° W., respectively. Those 
of the first set are the most prominent and are from 2 to 6 feet apart. 
Those of the second set are from 5 to 20 feet apart. Thus, it may be 
seen that, if a quarry face be opened parallel with the N". 45° E. joints, 
blocks of stone of almost any desired size may be obtained. Some 
prospecting with a core drill has been done at this place. The drilling 
extended to a depth of 45 feet. Some of the cores from the lower beds 
show practically the same color and texture of the upper beds. It is 
said that to the depth of the boring the grain is fairly uniform. 

The stripping here would consist almost wholly of soil, possibly a small 
amount of rock, and would amount to 1 to 5 feet. It is probable the 
slope in some places is sufficient to afford natural drainage, but in other 
instances it is not, and a quarry, if opened, would have to be drained 
by pumping. 

The outcrops occur at least a mile from the railroad, but the inter- 
vening country is level and a track could be run to them at minimum 
expense. 

Stone quite similar to the above is outcropping in many places, on 
land belonging to Dr. H. B. Shields along a small branch of Killett's 
Creek from f to If miles southwest of Carthage. It is probably of a 
somewhat more gray color than that on Mr. McNeill's land, and it seems 
to be slightly coarser in texture. 

The beds are from 2 to 6 feet thick and dip about 10° S. 35° E. 
The jointing here, as at the other place, is of two sets, N". 30° to 40° E. 
and N. 20° to 35° W. The northeast set is fairly close, from 1 to 15 
feet apart, averaging from 4 to 8. Those of the other set are from 2 



THE SANDSTONES AND QUARTZITES. 225 

to 60 feet and average perhaps 6 to 12. Stripping would vary from 1 
to 10 feet, according to locality. 

There are frequent large exposures of sandstone along McLendon's 
Creek, from 12 miles southwest of Carthage to where the creek flows 
into Deep Eiver about 15 miles north of Carthage. In many places the 
color, texture, amount of overlying worthless rock and soil, the dip or 
the closeness of the jointing, or some combination of these, renders the 
stone worthless. However, in a few localities outcrops of a fairly 
promising character may be seen. 

For about a mile above the bridge, where the old Plank wagon road 
crosses this creek, are some of the most favorable exposures on the creek. 
The rock here forms a ridge from 50 to 100 feet high, which slopes very 
abruptly up from the east bank of the creek, and it is in this steep slope 
that the most promising stone is showing. The beds vary in color from 
a decidedly red-brown, almost a brick-red, to a distinctly chocolate 
brown. The color for the most part is uniform throughout the same 
bed, though the different beds vary more or less. They dip about 10° S. 
60° E. and are cut, as usual, by three sets of joints, N. 30° E., N. 30° 
W., and north and south. The first two sets are of the most prominent 
and are of about equal importance, being from 2 to 8 feet apart, usually 
from 4 to 6. The third set, while well developed in some instances, is 
generally of little importance. The texture or grain varies but slightly, 
being from fine to medium. 

The amount of stripping would not be very heavy, as a rule. The form 
of the outcrops, the proximity to the creek, which could easily be made 
to furnish ample power for sawing the stone, and which would probably 
furnish sufficient power for operating the whole quarry, and the facilities 
for disposing of waste material, render some of these outcrops most 
favorable for quarrying. Some of the above-mentioned outcrops are on 
land belonging to D. A. McDonald, and others are on that of George 
Stead. 

Stone for use in the Moore County court-house was obtained from 
a small opening on Mr. Stead's land, about 3-J miles northwest of Carthage. 
The opening has been abandoned and is now filled with water, but many 
blocks on the edge of the old quarry show the stone to be of a remarkably 
uniform, dark reddish-brown color and fairly fine-grained. 

The dip is slight, the beds lying almost flat, and the jointing, as far 
as could be determined, quite the same as at the exposures along Mc- 
Lendon's Creek. The stripping is slight and consists almost wholly 
of soil. 

Many outcrops of stone, usually of a chocolate color, occur along a 



226 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

small branch of McLendonV Creek about 1J to 2 miles northwest of 
Carthage, on land belonging to Thomas Cole. Both color and texture 
appear to be fairly uniform. The beds vary in thickness from 1 to 6 
feet and dip from 10° to 20° S., 50° to 60° E. The joints are, for the 
most part, of two sets, K 15° or 20° E. and K 60° W. and are from 1 
to 6 feet apart. Some places, however, show 3 or even 4 sets of joints, 
the minor sets trending ~N. 65° E. and east and west. 

Along Deep Eiver, which flows for several miles across the Triassic 
formation in the northern part of Moore County, are many outcrops of 
sandstone, varying in color from an olive buff to reddish chocolate brown, 
and in texture from very fine-grained sandstone to fine conglomerate. 
The outcrops along the river and its tributaries — Crowley's Creek, Gov- 
ernor's Creek, and some other smaller streams — are generally in the 
form of bluffs or very abrupt slopes, varying in height from 30 to pos- 
sibly 140 feet. As a rule, each bed is more or less homogenous, but the 
separate beds differ very much in texture and color. In nearly every 
outcrop one or more thin strata of red shaly material occurs. The other 
beds may be either massive and uniform in both texture and color or 
they may be made up of thin " shelly " layers and vary greatly in color 
and texture. 

The dip here is greater than in the vicinity of Carthage, averaging 
about 15° S. 30° E. Joints are generally of two sets, trending on the 
average N. 30° W. and K 60° E., and from 1 to 8 feet apart. They cut 
the strata at about right angles to the bedding planes. In many places 
they are so numerous that the stone is worthless, but in a few places 
outcrops may be seen free enough from joints to be quarried profitably, 
other things being favorable. 

Some of the most favorable outcrops of this locality occur along 
Crowley Creek, on land belonging to J. L. Knight of Glendon. The 
beds of stone are exposed in either very abrupt slopes or bluffs along 
the creek and are from 30 to 100 feet high. They dip 15° S. 30 ± E. 
and are cut by joints running N. 30° W. and N. 60° E. and from 1 to 
10 feet apart. Two beds of rather uniform fine-grain, one of a leather- 
red color, the other of reddish chocolate-brown, each probably 6 or 7 
feet thick, separated by a thin bed of red shaly material, constitute the 
favorable stone of this exposure. These beds are near the top of the 
slope, and there are about 75 feet of unexposed slope below them which 
may also contain even better beds. 

Everything here is favorable for quarrying except the distance from the 
railroad (about 4 miles) and the all but impassable country roads. 
These last two conditions render the stone inaccessible at present. 



THE SANDSTONES AND QUARTZITES. 227 

THE SANEORD AREA. 
THE CARRINGTON-GONELLA QUARRY. 

In the northeastern part of this County, near Sanford, were located 
the most important quarries that ever were operated in the brownstone 
area of the State. These have, for the most part, long since ceased opera- 
tions. It is also here that we find the only sandstone quarry in actual 
operation in the State to-day, the Carrington-Gonella quarry, 1-J miles 
south of Sanford. 

The stone here is apparently in no way superior to that occurring in 
other places in the County, and, indeed, the natural outcrops are less 
favorable to quarry development. The reason for the development here 
is probably the nearness to the railroad. 

The Carrington and Gonella quarry is located about 1-J miles south 
of Sanford and about 200 yards west of the Seaboard Air Line Eailway. 
The opening is located near a little ravine in the southwestern slope of 
a low-lying hill, and is about 100 x 110 feet and 12 or 15 feet deep, 
being drained by a small pump (see PL XXX, A). 

Only one bed of workable stone has been exposed. This is 6 or 7 feet 
thick, dips slightly 40° or 50° W., and is of two distinct colors — a red 
and a grayish chocolate-brown. The upper two or three feet of the bed 
are of the first color, the remaining four or five feet of the brown shade. 
These colors are quite uniform, but gradually shade into each other. 
The red stone seems to be of a finer grain and to contain more clayey 
material than the brown. The texture of both varieties is fairly uniform, 
although there are a few small rounded pebbles seen here and there. 
This is especially true of the lower part of the brown portion of the 
bed, which, indeed, is directly overlying a 7 or 8 foot bed of conglomerate. 

There are two principal sets of joints, N. 60° ± W. and N. 30° E., 
and a third set east and west of slight importance. The important sets 
are from 2 to 15 feet apart — usually from 4 to 8. 

The stripping is so heavy on the north side of the opening that work 
cannot advance farther in that direction. On the west and south sides, 
the direction in which the work is advancing, it varies from 1 to 7 feet 
and, for the most part, consists only of soil. 

The quarry was opened in 1900 and has been operated continuously 
ever since. The working force, including stone cutters, is about 12 men. 
Stone is dressed at the quarry and hauled on wagons about 200 yards 
to a small spur of the railroad and is there loaded on the cars. The 
quarry is equipped with the following machinery: One 11 ft. gang saw; 
one 30 h. p. boiler; one 25 h. p. engine; one quarry bar; one I. & S. 
steam drill ; one 10 ton double drum hoist. 



228 BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 

Stone from this quarry has been used in the following buildings: 
Harrison Building, Augusta, Ga. ; Masonic Temple, Wilmington; A. & 
M. College, Ealeigh; Union Theological Seminary, Eichmond, Va.; 
Government Building, Newbern ; the First Baptist Church, Spartanburg, 
S. C. ; and in several other less important buildings. 

Crushing tests made at the Watertown Arsenal showed a strength of 
10,800 lbs. per square inch. 

There are a great many outcrops in roadsides and along streams north- 
west, west, and southwest of Sanford. At a few of the most promising 
of these some prospecting has been done, but apparently nothing of much 
value has been found. These outcrops are quite similar in nearly every 
feature and a description of one of them would, with very slight modi- 
fication, be applicable to any other. Hence, it is deemed unnecessary 
to describe more than one. 

The place thus selected is located on D. N.' Mclver's land about three- 
fourths of a mile northwest of Sanford. Here, in the side of a small hill, 
immediately north of a small stream, a prospect opening has been made. 
Two beds, the thickest of which is perhaps 6 feet, are exposed. They 
dip about 10° S. 30° W. and are broken by two sets of joints at right 
angles to the bedding planes of the strata from 1 to 6 feet apart and 
trending N. 60° ± W. and N". 30° E., respectively. The color of the 
stone is a very pretty reddish-brown and the grain is apparently uni- 
formly fine. The upper bed contains numerous clay " pockets," but the 
lower is nearly, if not quite, free from them. The color of this bed is 
somewhat darker than that of the upper, and is remarkably uniform. 
The stripping is slight and consists principally of soil. The slope in 
which the opening was made affords natural drainage. 

Several places where quarries were formerly in operation, but are now 
abandoned, were visited. The first of these was an opening about 200 
yards north of the Southern Eailway about 1-J miles northwest of San- 
ford. This place was once the site of the Carolina Brown Stone Com- 
pany's quarry. Only one bed of workable stone that varies more or less 
in color and very much in texture, is exposed. Stripping was heavy and 
the beds were broken by three quite prominent sets of joints, 2 to 8 feet 
apart and trending N. 35° ± W., K 45° ± E., and E. and W. The 
beds dip approximately 12° S. 10° E. There is no way of draining the 
opening except by pumping and also no place for disposal of waste. 

THE KACKLE AND LAWRENCE QUARRY. 

The opening, located about 1£ miles south of Sanford, is now a pond 
of stagnant water, and no stone could be seen in place, but blocks piled 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXX 




A. THE CARRINGTON-GONELLA SANDSTONE QUARRY NEAR SANDFORD, N. C. 




POST OFFICE BUILDING, WILMINGTON, N. C. BUILT OF SANDSTONE FROM NEAR WADESBORO, 

ANSON COUNTY. 



THE SANDSTONES AND QUARTZITES. 229 

up on the edge of the pond show that the material is uniform in neither 
color nor texture. The texture varies from fine, even-grained sandstone 
to fine conglomerate. Many of the blocks also show numerous clay- 
holes. The surrounding rocks dip perhaps 15° N". 60° W. and are cut 
by two sets of very close joints, trending ST. 60° W. and 5". 30° E. 
Stripping was also very heavy, and there was no means of draining the 
opening, except by pumping. 

CHATHAM COUNTY. 

The Triassic extends across the southern and eastern portion as a strip 
varying in width from 6 to 8 miles to 12 or 18 miles. Its general features 
do not differ from those of the same formation in the other counties. 
The stone may be seen outcropping along Deep Kiver and the small 
streams that flow into it, also along a portion of the Haw Eiver and 
along Hope Eiver, which flows over its beds for a distance of about 20 
miles. The formation here is also cut by numerous diabase dikes which 
always follow one or the other set of joints. The sandstone in this 
County does not differ essentially in either color, texture, or structure 
from that of Moore County. Thus, what has been said about the stone 
in that County will, with practically no modification, be applicable to 
this. 

No quarries are now in operation in this County, but it seems best 
to describe one or two places where more or less work has been done. 

An opening was made several years ago on the east bank of Deep 
Eiver, about 1-| miles southeast of Gulf. Considerable work has been 
done here and more or less machinery is now at the place, but it has 
evidently been abandoned for several years. The opening is made in a 
slope rising rather abruptly about 25 feet above the river. Only one 
bed of anything like workable stone is exposed. It is of a variable buff 
or yellowish-gray color, in places almost white, is probably 7 or 8 feet 
thick, is fairly massive, and dips 15° S. 60° E. The texture of the stone 
is rather coarse and is somewhat variable. This bed is remarkably free 
from joints, having only one prominent set, not close, trending N. 30° 
W., and another subordinate set running K. 35° ± E. The stripping 
amounts to from 8 to 15 feet and consists of both soil and worthless 
stone. The work would necessarily advance in the direction of the dip, 
thus causing the stripping to increase very rapidly. The opening is, 
unfortunately, located so near the river that during freshets the whole 
place is overflowed. 

In many other places along Deep Eiver and the small streams that 
flow into it, outcrops of the usual red and chocolate-colored sandstone 



230 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

may be seen. The beds, in some instances, are fairly uniform in color 
and texture, while, in others, there is much variation in both. Some 
of the beds thus exposed are so located that the stripping would be very 
light, but in practically every instance the beds dip so steeply that the 
stripping would increase rapidly from the start and soon become so heavy 
that it could not be economically removed. In some cases the joints, 
which, as a rule, are from 2 to 10 feet apart, are such that blocks of 
workable dimensions might be obtained, while in others they are so close 
that the stone is worthless. If exploitation should show up stone of 
such a character along this river as to warrant quarrying, the stone could 
be readily and cheaply taken to shipping points by means of barges. 
This fact renders much of the Triassic area that could not be otherwise 
reached quite accessible. 

A small opening has been made in the east bank of Deep Eiver, about 
three-fourths of a mile northwest of Cumnock (formerly Egypt), on the 
Southern Eailway. The opening is in a very steep slope, almost a bluff, 
about 25 feet high. Only one bed of workable stone is exposed. This is oi 
a fairly uniform red-brown color, and of fine, even grain. It does, however, 
generally show very slight stratification lines — so fine that they are not 
discernible except upon the closest scrutiny. There are also a few small 
clay holes in the upper portion of the bed, but they seem to be confined 
to the upper 8 or 10 inches, as none were seen in the middle or lower 
portions. This bed dips 10° S. 10° E. and is cut by three sets of vertical 
joints, trending N"; 45° E., east and west, and north and south, and 
varying from 4 to 15 feet apart. The last mentioned set is not very well 
developed and is of little importance. Stripping would amount to from 
4 to 10 feet, and would increase as work would proceed, since it must 
advance in the direction of the dip of the strata. 

The best grade of stone from this opening weathers well. In a small 
cemetery near the opening are a few headstones made from it, which 
though exposed to the weather for years, still show no signs of dis- 
integration. 

In other places near this one, especially in some small cuts on the 
Chatham Coal and Iron Company's railroad, east of Cumnock, are ex- 
posures of similar stone. What has been said about the above opening 
is, with practically no modification, applicable to any one or all of them. 

ORANGE COUNTY. 

Only a very small area of the Triassic is within this County. This 
is in the extreme southeastern corner. 

Though the stone is outcropping in several places along a small trib- 



THE SANDSTONES AND QUARTZITES. 231 

utary of Hope Biver, no exposures of sufficient importance to warrant 
quarrying were seen, the stone not being uniform in either color or 
texture. It is also so badly jointed as to condemn it, even were other 
qualities satisfactory. 

In only one place within the County has any quarrying been done. 
The opening is located about 1^ miles southeast of Chapel Hill and was 
made over a century ago in order to get stone for use in the buildings 
of the State University, and hence is known as the " University Quarry." 
The beds are from 4 to 6 feet thick, of a fairly uniform purplish gray 
color, but of variable texture. It is cut by four distinct sets of vertical 
joints, from 2 to 10 feet apart and trending north and south, east and 
west, 1ST. 30° W., and N". 60° E. respectively. The first two sets are most 
prominent, the others being of small importance. The peculiar color of 
the stone is doubtless due to the influence of a large diabase dike fol- 
lowing the north and south joints only a few feet from the opening. 

WAKE COUNTY. 

The sandstone formation extends entirely across the western part of 
this County, but nothing in the way of systematic quarrying has ever 
been attempted and, in fact, very little prospecting or exploratory work 
has been done. The stone does not differ in any important particular 
from that of the other counties that include Triassic areas. 

Many outcrops were visited and the general features of the stone were 
found to be so uniform that it is thought necessary to include descrip- 
tions of but two or three places that appear to be typical. 

On a farm belonging to W. C. Young, 2-J miles northwest of 
Morrisville is a large exposure of sandstone from which stone for founda- 
tions, chimneys, etc., has been taken. The stone exposed is in beds from 
a few inches to probably 5 feet in thickness, the upper layers of which 
are badly weathered and more or less shaly. The fresh beds are fairly 
uniform in texture, generally fine-grained, but are of two distinct colors 
— a reddish-brown and a kind of chocolate-brown. The beds dip from 
7° to 10° S. 60° E. There are, as usual, three distinct sets of joints, 
N". 60° W., ~N. 45° E., and north and south, so close together that it 
would be impossible to get out dimension stone. In addition, all the 
stone exposed has been badly mashed and sheared; nearly every joint 
plane shows more or less siickensiding. 

About 1J miles west of the above place, on land belonging to W. M. 
Howard is an outcrop, the best bed of which is perhaps 5 feet thick. 
The texture is from medium grain to fine conglomerate, the conglomerate 
being the lower 6 or 8 inches of the bed. The red-brown color is here and 



232 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

there marked with purplish gray streaks. There are but two series of 
joints, from 2 to 10 feet apart and trending N". 30° W. and 1ST. 60° E. 
respectively. The outcrop is in the west side of a small hill or ridge 
that slopes gradually upward from a small branch in the bed of which 
similar stone is exposed for some distance both above and below the 
outcrop described. 

DURHAM COUNTY. 

By referring to the map (PI. XXIX), it may be seen that practically 
the southeast half of this County is of the Triassic formation. The rocks 
here are closely jointed, probably more so than in any other county, 
there being always two well-defined series of joints, usually three, and 
sometimes four. The beds vary in thickness from a few inches to 8 or 
10 feet, and dip, usually about 10°, in a southeasterly direction. The 
texture of the sandstone is possibly a little more uniform than elsewhere, 
but the color is variable, being from almost a grayish flesh-color or 
grayish pink to a distinct purplish chocolate-brown. 

Excepting that of Anson County, the Triassic of this county contains 
more and larger diabase dikes than any other county in the State. These 
dikes always follow a set of joints, generally a northwest, though quite 
frequently a northeast set. They vary from a few inches to over 500 
feet in width. 

No systematic quarrying has ever been done in this county, but here 
and there small openings have been made to supply stone for local uses. 
Some of these and some of the natural outcrops that may be considered 
typical will be described. 

On A. Bigsby's land, about a quarter of a mile southwest of Brassfield, 
is quite an extensive outcrop of sandstone of a light chocolate color, form- 
ing a large bluff along the east side of G-oose Creek. The color and tex- 
ture are fairly uniform in the same bed, but vary somewhat in the differ- 
ent beds. The beds exposed are from 2 to 6 feet thick and are cut by two 
sets of vertical joints trending N". 30° E. and N. 30° W., respectively, 
from 1 to 10 feet apart. The amount of stripping, consisting of both 
soil and worthless rock, would be between 4 and 8 feet at the beginning, 
but would increase rapidly, since the work would have to advance into 
the hill and also in the direction of the dip, which, however, is slight, 
about 5°. 

Some work has been done here in order to secure stone for local uses, 
but nothing in the way of systematic quarrying has been attempted, and 
it has apparently been several years since the last work was clone. 

A few paces west of the above outcrop, just across the creek, is a small 



THE SANDSTONES AND QUARTZITES. 233 

opening made years ago to get stone for buildings at Kaleigh. Only 
one bed of workable stone, about 6 feet thick, is exposed. This bed is 
a compact, even-grained stone, of a fairly uniform grayish pink or flesh 
color, containing considerable mica (muscovite). The joints here, while 
having the same trend as those of the opening just described, are, on 
the average, farther apart. The stone also appears to lie practically 
horizontal. The stripping, too, is slight, 3 to 5 feet, and consists almost 
entirely of soil. The opening is in the narrow creek valley aod is only 
slightly, if any, above the level of the stream bed. Thus, considerable 
trouble from water might be expected if the stone should ever be quarried 
at this point. 

There are several other outcrops of sandstone along this creek similar 
in practically every respect to those just described. The jointing, while 
always close, is apparently, in some places such that dimension stone 
could be obtained, if other features should be favorable. However, in 
every place, the joints are close enough to be considered a serious defect 
of the stone, and in many instances they render it absolutely worthless. 

Some openings were made near Durham years ago to supply stone 
for foundations, trimmings, etc., for local use. The most prominent 
of these, while hardly more than prospect openings, are spoken of as 
quarries. They are the Kobt. I. Kogers' Quarry and Duke's Quarry, and 
are located 1-J or 2 miles east of Durham. 

The Eobt. I. Sogers' Quarry is an old opening which has been made 
in the base of a low-lying hill about 2 miles east of Durham. Only one 
bed of stone was worked. It is about 5 feet thick, is fairly uniform 
in texture, is cut by four sets of quite prominent joints trending N". 
15° E., N. 65° W., N. 55° E., and east and west (the 1ST. 15° E. set 
from 1 to 3 feet apart, others from 5 to 12), and dips about 10° E. 
The color is from a pinkish brown to a decided chocolate brown. Strip- 
ping, from 6 to 10 feet at present, but would increase rapidly, since work 
must advance in the direction of the dip. 

Duke's Quarry is located about 2\ miles northeast of Durham. The 
beds that were worked, here are somewhat thicker than those above de- 
scribed; perhaps from 7 to 8 feet. The rock is also similar in texture 
and color, except that this stone is somewhat darker, more of a purplish 
hue, and is not so uniform. The joints are the same as those of the 
Eogers' opening, having exactly the same trend, except that the east 
and west set is apparently not developed. Dip is 10° E. Stripping 
amounts to from 7 to 10 feet now and must increase very materially as 
work might proceed, for reasons already noted. 



234 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

STOKES AND ROCKINGHAM COUNTIES. 

It will be seen by referring to the map, PI. XXIX, that a large area of 
Triassic sandstone is indicated as occurring in the Dan Eiver ; valley in 
Stokes and Eockingham counties. This area of Triassic rocks is first 
met with near Germanton, a station on the Southern Eailway. It ex- 
tends from this point as a narrow belt varying in width from 3 to 5 
miles, northeastwardly to the North Carolina- Virginia boundary line, 
a distance of about 100 miles. 

The beds of stone dip rather steeply toward the northwest, probably 
30° to 50°, and are cut by two to four sets of very closely spaced joints. 
They vary greatly in both color and texture. The former variation is 
from almost black through many shades of brown to a rust-like red, 
there being apparently no regularity whatever in regard to color. In 
texture the beds vary from a nearly typical carbonaceous shale, coal- 
bearing in places, through impure sandstones of varying fineness into a 
typical coarse conglomerate. In thickness the beds also vary greatly 
from only a few inches to many feet. These features make it quite 
certain that this area contains no stone that could be quarried for any 
but purely local use and then only for the lowest class of work, such as 
culverts, bridge piers and in the construction of dams. Only a few small 
openings have been made, and these were to secure a rock for some of 
the purposes just mentioned. 

This Triassic area, like the large area lying to the east, is cut by 
numerous diabase dikes, many of which are very large and will furnish 
vast quantities of excellent road metal. The limited amount of time 
available for field study in this section made it possible to visit only a 
few of the most important of these dikes, see p. 237. 

TESTS ON SANFORD AND WADESBORO SANDSTONES. 3 

It has long been known that clastic rocks, that is, rocks of the nature 
of sandstones, of high absorptive power, undergo a loss of strength 
through the absorption of water, and at times an additional loss through 
freezing when in a saturated condition. Of recent tests along these 
lines, those of Prof. Anson Marston, of the State Agricultural College of 
Iowa, are of greatest importance so far as the present writer has informa- 
tion. 2 The results obtained by Prof. Marston were of so striking a 

8 These tests were made by or tinder the direct supervision of Mr. Laney. 
4 See Proc. 10th Ann. Meeting of the Iowa Engineering Society, Jan., 1898, pp. 
123-136. 



THE SANDSTONES AND QUARTZITES. 235 

nature, it was thought worth while to repeat the tests in part on North 
Carolina materials. The facts obtained, and as given below, fully sub- 
stantiate those obtained by Prof. Marston. 

A series of twelve accurately prepared 2-inch cubes of sandstone, from 
Sanford and Wadesboro, were selected, six from each source. From 
each series two were crushed dry, two when saturated with water and two 
after soaking in water and then being frozen. Incidentally the specific 
gravity and weight per cubic foot were obtained. 

To secure saturation and at the same time ascertain the specific 
gravity, two cubes from each locality wer£ first dried to a constant weight ; 
they were then immersed in distilled water for 48 hours, at the end of 
which time the air was exhausted from the pores of the stone until a 
vacuum of 9 inches was obtained. Under these conditions the cubes were 
allowed to remain for another 48 hours, when they were removed, weighed 
in distilled water, and the specific gravity calculated by the ordinary 
method. The results are given in the table on p. 236. These same cubes 
were used, in their saturated condition, for pressure tests, and showed 
a decided weakening as noted later. 

For the freezing tests, four more cubes of precisely the same nature 
were selected and placed first in a pan of distilled water, where they 
were allowed to soak for 72 hours. They were then removed and quickly 
weighed, after wiping from the surface the excess of water by bibulous 
paper. They were then placed in a basin containing a small amount 
of water and subjected to ten alternate freezings and thawings, the freez- 
ing process being carried on in the cold storage rooms of the Washington 
Market, where a temperature of from 5° above to 6° below zero F. pre- 
vailed. The figures below show the loss in weight of the cubes through 
the forcing off of small particles by the expansive power of the water 
when passing into the condition of ice. The results, it will be noted, 
are very slight. 

Freezing Test on 2-Inch Cubes of Sandstone. 



Number 
of cube. 


Weight before 
freezing 1 . 


Weight after 
freezing. 


Loss. 


5. 


325.73 grams. 


324.995 


0.735 


6. 


320.86 


320.52 


0.34 


11. 


323.55 


322.89 


0.66 


12. 


326.85 


326.135 


0.71 



After the tenth freezing and thawing, and the weighings, above noted, 
the cubes still full of water were submitted to the same crushing tests 



236 



BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 



as the others, 
table. 



The results of these tests are given in the following 



Crushing Tests on 2-Inch Cubes of Sandstone, Dry, Wet and After Freezing. 



Number 
of cube. 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 
10. 
11. 
12. 



Specific 
Gravity. 



2.635 I. 
2.645 » 



2.625 



Wt. per 
cu. ft. Absorption. 



162.7 



4.20 



3.71 



Condition. 

Dry. 
<< 

Wet. 
After freezing. 

Dry. 

Wet. 
After freezing. 



Crushing 
Load. 

41,290 
44,600 
27,850 
23,350 
26,500 
27,500 
49,000 
45,330 
22,550 
26,850 
25,150 
26,000 



Strength 
per sq. in. 

10,322 
11,150 

6,962 

5,837 

6,625 

6,875 
12,250 
11,232 

5,637 

6,712 

6,287 

6,500 



Remarks. 

Failed gradually. 
<< << 

Burst in pieces. 
Failed gradually. 

Failed suddenly. 
Failed gradually. 



The results shown in the above table somewhat exceeded expectations 
so far as related to loss of strength by saturating with water only, but 
the loss by freezing was not as great as was expected. Indeed, as will 
be noted, the cube that had been frozen is in some cases stronger than the 
corresponding one that had been simply saturated. The difference is, 
however, slight and the number of tests too few to permit the deduction 
of anything of value. The very great loss in strength, averaging up- 
wards of 44 per cent by simple saturation with water, is, however, a 
very important matter and one that should receive serious consideration 
whenever stone is to be placed in a position like a foundation for bridge 
abutment. It should be noted, however, that a strength of even 6,000 
lbs. per square inch is sufficient for ordinary construction. It was note- 
worthy in the tests that the dry cubes for the most part failed suddenly, 
while the wet simply yielded slowly and gradually (see PI. XXXI). 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXXI 














10 



12 



FORMS ASSUMED BY 2-INCH CUBES OF SANDSTONE AFTER SUBJECTION TO CRUSHING TEST. 



CHAPTER VII. 

DIKES PENETRATING THE SANDSTONES. 

One of the most striking features of the Triassic areas of the State is 
the great number of dikes of igneous rocks which penetrate the sand- 
stones. These dikes are scattered throughout the whole formation, more 
or less irregularly of course, in such numbers that no considerable dis- 
trict was found in which they do not occur. But they are much more 
numerous in some localities than in others. For example, in Anson 
County, a section across the sandstone along the Seaboard Air Line 
Railway, from near Lilesville westward to near Polkton, a distance of 
about 15 miles, shows no less than 50 dikes varying in size from a few 
inches to over 100 feet. 1 Since for more than half the distance the 
railroad made no cuts or was constructed by making fills, thus not 
uncovering the rocks or covering them still deeper for the greater part 
of this distance, it is safe to assume that at least 100 dikes would be 
showing in this distance of 15 miles, if the rock were exposed throughout 
the whole distance. An example of the other extreme is found near 
Sanford in Moore County, where a section of nearly 4 miles fails to 
show a single dike. 

There are two principal systems of joints developed in the rocks of 
this area, averaging N. 35° or 40° W. and N. 45°-65° E., generally 
approximating N. 30° W. and N. 60° E. In addition to these, there are 
two subordinate systems trending north and south and east and west 
respectively. 

The dikes invariably follow one or the other of these joint systems, 
in the majority of cases a northwest set. Out of 44 important dikes that 
were carefully measured, 27 had a northwest trend, 10 were trending 
northeast, and the remaining 7 had an approximately north and south 
trend. 2 

At many of the dikes, especially in Anson County, where railroad cuts 
have given good exposures of both country-rock and dike, there occur 
sudden changes of dip of the sandstone beds adjacent to the dikes, thus 

1 1. C. Russell, Bull. No. 85, U. S. Geol. Survey, pp. 94-95. 

2 For trends of joints and dikes of the Triassic area, see pp. 241-243, and for the 
other areas, see pp. 184-186. 
17 



238 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

indicating that the igneous material was extruded along displacements. 
Faulting of the sandstone beds throughout the whole Triassic area is 
apparently quite common. 3 

The dike material is always, as far as determined, a typical diabase, 
generally, rich in olivine. Sometimes the rock is fine-grained, especially 
in the narrow dikes, while again, in the large ones, the grain may be 
medium or quite coarse. Also each dike of any considerable size always 
shows a very fine-grained area at the contacts with the country-rock, 
where the magma would be cooled most rapidly, and an interior of much 
coarser grain. 

In the following notes, only those dikes are mentioned in detail which 
are large enough to be of more or less economic importance. 

ANSON COUNTY. 

In the western limits of the town of Wadesboro, near a negro church, 
a dike more than 100 feet wide is in evidence. 

About 1 mile north of Wadesboro and only a short distance from the 
Seaboard Air Line Eailway are two large and very favorably situated 
dikes, each about 125 feet wide. One is exposed in the north end of the 
old Linehan quarry excavation, and the other is about 300 yards east of 
it. These dikes are so located that they will furnish a great deal of 
excellent road metal. 

At Brown's Creek, about 7J miles northwest of Wadesboro is a diabase 
dike over 500 feet wide. This is probably one of the largest dikes in the 
whole Triassic area of the State. This dike, although it is deeply 
weathered, will furnish a vast quantity of good road material. Eesults 
of tests of this rock for road material are given on p. 265. 

On Jones' Creek in the southeastern part of the County is a large dike 
of trap rock (hypersthene gabbro) that will furnish a great amount of 
road metal practically as good as that of the diabase dikes. This dike 
is probably a continuation of the gabbro dike near Steele's Cotton Mill 
in the western part of Eichmond County. 

CHATHAM COUNTY. 

Only one dike was seen in this county of sufficient size to be of 
economic importance. This one, a typical diabase, occurs about 200 
yards southeast of the railway station at Gulf. It has a width of 
about 200 feet, but is so deeply weathered that no estimate of the avail- 
able road material can be given. Other dikes are exposed at several places 
along the Seaboard Air Line Eailway, between Sanford and Merry Oaks, 
a few of which are apparently large enough to be of some value. 

3 I. C. Russell, Bull. No. 85, TJ. S. Geol. Survey, p. 94. 



DIKES PENETRATING THE SANDSTONES. 239 

DURHAM COUNTY. 

Only a very little time* was spent in examining the supply of road 
material of this County, and consequently but a very few of the largest 
and most easily accessible dikes were visited. The County apparently 
contains as much trap rock as any other of the Triassic counties of the 
State, but as a rule the dikes seem to be small. 

The following are some of the dikes that are considered large enough 
to be of economic value. 

The Southern Eailway crosses a deeply weathered diabase dike over 
500 feet wide, about 3 miles northwest of Durham. This dike will 
furnish a vast deal of excellent road metal. 

The Durham-Baleigh wagon road, running southeast from Durham, 
crosses several dikes, three of which having each a width of over 100 
feet and located 2, 2^ and 6 miles southeast of Durham, are probably 
worth mentioning. Practically all the available surface material from 
these dikes has been used and the dikes are so deeply weathered that no 
reliable estimate of the material they will furnish can be made. 

MOORE COUNTY. 

The dikes of this County are quite numerous and also, as a rule, are 
large. The following list of a few of the largest and most promising 
dikes gives the location of some of the best road metal in the County. 

On the old " Stage " road, near a negro church, about 3 miles west of 
Carthage is a 75 foot dike of typical diabase. 

Near Kelley's old mill on McLendon's Creek about 3^ miles north- 
west of Carthage is a very promising dike 125 feet wide. This dike is 
apparently in fair condition as regards weathering, and it will, with no 
great amount of labor and expense, furnish a vast amount of excellent 
stone. 

About a quarter mile south of the old " Stage " road, 8 miles southwest 
of Carthage, there is a diabase dike probably 250 feet wide. It extends 
across the country for some distance as a low ridge, and while only a 
few boulders are to be seen on the surface, it is probable that a little 
exploratory work will reveal a great amount of excellent road metal. 

Near Black's old mill on Little Eiver, about 7 miles south of Carthage 
is another very prominent dike over 150 feet wide. This dike, apparently 
in excellent condition, forms a ridge which stands about 30 feet above 
the surrounding country, and is thus very favorably located for quarry- 
ing. The rock is hard, tough and quite fresh and is an excellent road 
metal. Eesults of tests of this rock for road material are given on 
p. 266. 



240 BUILDING AND OKNAMENTAL STONES OF NORTH CAROLINA. 

In the bed of a small branch of Killetts' Creek, three-quarters of a mile 
southwest of Carthage, a diabase dike about 100 feet wide is exposed. 

A large and very favorably located dike 150 feet in width is crossed 
by Mill Swamp Creek about three-fourths of a mile north of Carthage. 
This dike extends across the country for more than a mile as a low ridge. 
The rock is apparently in excellent condition, hard and fresh, and so 
located that it could be readily quarried. Results of tests of this rock 
for road material are given on p. 266. 

A large dike of good, fresh diabase is seen in the banks of Deep Eiver 
near the mouth of McLendon's Creek, about 9 miles north of Carthage. 
This dike has a width of about 200 feet and occurs in such a manner 
as to be quarried with little difficulty. 

The Deep Eiver wagon road leading north from Carthage crosses 
three large diabase dikes. These are all in fair condition and will furnish 
vast quantities of rock. They are 200 feet, 150 feet and 100 feet re- 
spectively in width and are located 3, 4, and 6 miles from Carthage. 

ORANGE COUNTY. 

Only one dike of any importance was visited in this county. It is 
located near the old "University Quarry" (see p. 231), is about 150 
feet wide, and is so located that it could be cheaply quarried. It occurs 
about 1-J miles east of Chapel Hill. Eesults of tests of this rock for road 
material are given on p. 266. 

In the following tables some data regarding the trend of the joint 
systems and the dikes have been tabulated to show the relation of the 
two. 



DIKES PENETRATING THE SANDSTONES. 



241 



TABLE SHOWING THE DISTRIBUTION OF DIKES PENETRATING THE SANDSTONES AND 

THEIR RELATION TO THE JOINTING. 

Moore County. 

Trend of Joints. Dikes. 



Locality. Major set. 

Carrington & Gonella's quarry, one and a 

half miles south of Sanford ..N. 60° ±W. 

Rackle & Lawrence's old quarry, one mile 

south of Sanford N. 60° +"W. 

D. N. Mclver's land, three-quarters mile 

northwest of Sanford N. 60° ±W. 

Carolina Brown Stone Co.'s old quarry, 

one and a half miles northwest of 

Sanford N. 30-40° W. 

Cut on Southern Railway, three miles 

southeast of Cumnock N. 30° W. 

Old quarry on Deep River, one and a half 

miles southeast of Gulf N. 30° W. 

Old quarry on Deep River, three-quarters 

of a mile west of Cumnock N. 45° E. 

Mr. Stead's land, four miles northwest of 

Carthage N. 30° W. 

Mr. McDonald's land, one-half mile north 

of above N. 30° W. 

A. H. McNeill's land, three-quarters mile 

west of Carthage N. 45° E. 

Thos. Cole's land, one and a half miles 

northwest of Carthage N. 15° E. 

Thos. Cole's land, two miles northwest of 

Carthage N. 15-45° E. 

Thos. Cole's land, two and a quarter 

miles northwest of Carthage N. 60° E. 

Kelley's old mill on McLendon's creek, 

four and a half miles northwest of 

Carthage N. 30° W. 

One-half mile southeast of above N. 30° W. 

W. C. Bryant's land on McLendon's creek, 

eleven miles southwest of Carthage.. N. 45° E. 
One mile north of above, along west 

bank of creek N. 45° E. 

A. H. McNeill's land on Suck Creek, nine 
and a half miles southwest of 

Carthage N. 30° E. 

J. L. Knight's land, Crowley Creek, three 

miles south of Glendon N. 30° W. 

Near steel bridge, across Deep River, ten 

miles north of Carthage N. 25° ±W. 

One-half mile southwest of the above N. 30° W. 

Near covered bridge across McLendon's 

creek, three and a half miles north- 
west of Carthage N. 30° ± W. 

Near negro church Stage road, three miles 

northwest of Carthage Sandstone not exposed at dike 

One-half mile south of the dike near the 

bridge N. 30° W. N. 60° E. 

One-quarter mile south of Stage road, 

eight miles southwest of Carthage Sandstone not exposed at dike. 



Second set. 


Third set. 


N. 30° E. 


E. & W. 


N. 30° E. 




N. 30° E. 




N. 40-50° E. 


E. &W. 


N. 40-50° E. 




N. 30-40° E. 




E. &W. 


N. &S. 


N. 30° E. 


N. &S. 


N. 60° E. 




N. 50° W. 




N. 60° W. 




N. 65° E. 


N. 50-60° W 


N. 50° W. 


E. &W. 


N. 60° E. 




N. 60° E. 




N. 45° W. 


N. &S. 


N. 45° W. 


N. &S. 


N. 45° W. 




N. 60° E. 




N. 60° E. 




N. 60° E. 




N. 60° E. 





Fourth 



Width. 



50-4- 



E. &W. 



125 



N. 80° E. 
N. 80° E. 



75 + 



Trend. 



N. 30° W. 



N. 30° W. 



N. 30° W. 



75 ± 


N. 30° W. 


75 ± 


N. 25° ±W. 


L25 


N. 30° W. 


200-300 


N. 45° ±E. 



242 



BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 



Trend of Joints. 



Second set. Third set. 



Locality. Major set. 

Black's old mill on Little River, seven 

miles south of Carthage *Dike is in Coastal Plain. 

Deep River wagon road, three-quarters of 

a mile northwest of Carthage 

Deep River wagon road, three miles 

northwest of Carthage N. 50° E. N. 30° W. 

Deep River wagon road, four miles north- 
west of Carthage N. 30° W. N. 60° E. (?) 

Deep River wagon road, five and three- 
quarters miles northwest of Carthage. N. 30° W. N. 60° E. 

Near mouth of McLendon's creek, nine 

miles northwest of Carthage N. 30° W. N. 60° E. 

Branch of Killett's creek, three-quarters 

mile south of Carthage N. 20° W. N. 50° E. ( ?) 

Branch of Killett's creek, one and a quar- 
ter miles south of Carthage N. 30° W. N. 45° E. 

Carthage-Blacks' mill wagon road, one 

and a half miles .south of Carthage.. N. 20° W. (?) 



N. &S. 



N. &S. 



Fourth set. 



Width. 
200 
150 
200 
100 
100 

200 (?) 
100 



Trend. 

N. 30° ±W. 
N. &S. 
N. 50°E. 
N. 30° W. 
N. 30° W. 
N. &S. (?) 
N. 20° W. 



N. 20° W. 



* This dike is very near the contact between the Triassic and Coastal Plains formations. Joints in the standstone near 
this dike have the trend N. 30° ± W., N. 50° E. 



Anson County. 



Old Linehan quarry, one mile north of 

Wadesboro N. 30° W. 

300 yards northeast of Linehan quarry N. 30° W. 

W. A. Polk's quarry, one and a quarter 

miles northwest of Wadesboro .N. 30° W. 

One-quarter mile southeast of Polk 

quarry N. 30° W. 

Ansonville road, one mile northwest of 

Wadesboro N. 30° W. 

Polkton road, one mile ± northwest of 

Wadesboro N. 30° W. 

Polkton road, two miles west of Wades- 
boro N. 30° W. 

Polkton road, two and a quarter miles 

west of Wadesboro N. 30° ± W. 

Polkton road, three miles west of Wades- 
boro N. 30° ±W. 

Polkton road, three and a quarter miles 

west of Wadesboro N. 30° ±W. 

Polkton road, three and a half miles west 

of Wadesboro — Boggan's cut N. 30° + W. 

Brown's Creek, seven and a half miles 

northwest of Wadesboro N. 40° ±W. (?) N. 50° ±E. (?) 

Frank Hammond's quarry, two miles 

southwest of Wadesboro N. 40° ± W. N. 35° ±E 

Gould's Fork, three miles northwest of 

Wadesboro N. 55° ±W. N. 30° E. N. & S. 

Wm. Parson's quarry, one-half mile west 

of Wadesboro N.55°±W. N. 30° E. 

I. Horton's quarry, three-quarters mile 

southwest of Wadesboro N. 55° ± W. N. 30° E. 

Near negro church in west limits of 

Wadesboro Sandstone not exposed at dike 



N. 60° E. 






N. 60° E. 






N. 60° E. 






N. 60° E. 






N. 60° E. 


N. 


&S. 


N. 60° E. 


N. 


&S. 


N. 60° E. 


N. 


&s. 


N. 60° ±E. 


N. 


&s. 


N. 60° +E. 






N. 60° +E. 






N. 60° +E. 







100 + 
100 + 



N. 30° W. 
N. 30° W. 



N. 30° W 

N. &S. 
N. &S. 



I Two small 

1 dikes. N. & S. 

i 



25 
' 25 

f 20 



N. 35° W. 
N. 35° W. 
N. 35° W. 
* 20 N. 35° W. 

Many small 

N. 30-35° W. 
N. 30-35° W. 
N. 30-35° W. 
N. 30-35° W. 
N. 30-35° W. 
N. 45° W. (?) 




N. 40°-+-W. 



DIKES PENETRATING THE SANDSTONES. 



243 



Durham County. 

Trend of Joints. 



Locality. Major set. Second set. Third set. 

R. I. Rogers' quarry, two miles east of 

Durham N.15° E. N. 60-70° W. N. 55° E. 

Duke's quarry, two and a half miles north- 
east of Durham N.15° E. N. 60° W. N. 45° E. 

A. Rigsby's land, one-quarter mile south- 
west of Brassfield N. 30° E. N. 30° W. 

One-quarter mile northwest of above N. 30° E. N. 30° W. 

Morris land, three and a half miles south- 
east of Durham N. 30-40° E. N. 30-40° W. N. & S. 

Durham-Brassfield road, six miles south- 
east of Durham N. 35° E. N. 30° W. (?) ........ 

Right-of-way Southern Railway, three 

miles northwest of Durham Sandstone not exposed at dike 

Hillsboro road, three and a half miles 

northwest of Durham " " " 

Durham-Brassfield road, two miles east of 

Durham " " " 

Durham-Raleigh road, two and a half 

miles east of Durham " " " 



E. & W. 



Dikes. 



Fourth set. Width. 
E. & W. 



Trend. 



100 + N. 35° E. 

600 ± N. 15-30° E. 

75 N. 45° E. 

100+ N. 25° ±E. 

150 N. 60° E. 



University quarry, one and a half miles 

east of Chapel Hill N. & S. 

Raleigh road, three-quarters mile east of 

Chapel Hill 

At trestle Southern Railway, three-quar- 
ters mile north of Chapel Hill 



Orange County. 



&w. 



N. 30° W. 



N. 60° E. 



150 

20; 

50 



N. &S. 

N. 15-20° W. 

N. 45° E. 



Wake County. 



W. C. Young's farm, two and a half 

miles northwest of Morrisville N. 60° W. N. 45° E. N. & S. 

One and a half miles west of the above 

locality N. 30? W. N. 60° E. N. & S. (?) 

Mr. Proctor's land, three miles northwest 

of Morrisville Sandstone not exposed at dike. 



50 



N. 20° W. 



Chatham County. 
W. N. 30-40° e 



Abandoned quarry on Deep River, one 
and a half miles southeast of Gulf N. 

Small quarry on Deep River, three-quar- 
ters mile west of Cumnock N. 45° E. E. & W. N. & S. 

Two hundred yards southeast of Gulf Sandstone not exposed at dike. 



200 + 



N. 45° W. (?) 



Rockingham County. 



Leakesville road, one mile northeast of 

Madison N. 20° E.f 

Leakesville road, eight miles northeast of 

Madison N. 20° E.f 



100 
200 



N. 20° E. 
N. 20° E. 



* The sandstone was not exposed at either of these dikes, but observations made in other places show that a promi- 
nent set of joints had a trend of N. 20° E. 

f Dikes in crystalline rocks, but having the same trend of the most prominent set of joints in the sandstone nearby. 



CHAPTER VIII. 

METHODS OF QUAKKYING AND WOKKING STONE. 

The past twenty years have brought about a very marked change in the 
stone working industries; a change due mainly to the introduction of 
machinery. It is only in the smaller quarries and those catering to but 
a local market that recourse is still had to the old time hand drill. On 
a large scale, machinery does the work quicker, better and cheaper. Of 
the many machines now on the market, reference will here be made only 
to those in most general use. 

In the quarrying of granite and other hard stone it is customary to 
drill a number of holes along the line it is desired that the stone shall 
break. These are then charged with a slow burning powder and fired 
simultaneously. By this means not merely is direction given but the 
force of the explosion is distributed over a considerable surface, thereby 
lessening the danger of shattering the stone. The drill holes in this 
work are commonly driven by a steam drill mounted on a tripod as 
shown in Figs. 5 and 6, and which is connected with the steam boiler by 
means of a flexible hose permitting the moving of the drill with compara- 
tive freedom. In a few cases, as at the Mt. Airy quarries, a different 
expedient is resorted to. This is explained on p. 157. 

In quarrying soft stone, such as limestone, marble and sandstone, the 
use of powder is now almost wholly done away with, the stone being freed 
from the quarry bed by means of channelling and gadding machines. Sev- 
eral types of channelling machines are now in use. The oldest, and the one 
commonly used in the Vermont marble regions, is the Wardwell machine, 
shown in Fig. 7. This, as will be noted, is essentially a locomotive sup- 
plied on either side with gangs of cutting drills which are lifted and 
dropped as the machine travels backward and forward over the temporary 
tracks. Another type of machine for the same work, is the Ingersoll- 
Sargeant channeller shown in Fig. 8. This has the advantage that the 
drills can be inclined at any angle. The cut is made as a continuous 
slot some 1| to 2 inches in width, and of any desired depth up to 6 or 
8 feet. After the channelling machines have done their work the blocks 
are freed from the bed by means of wedges introduced into a series of 
holes at right angles with the first cut. This underdrilling or under- 



METHODS OF QUARRYING AND WORKING STONE. 245 



1246 




'ig. 5. — Eclipse rock drill. 



246 



BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 



cutting is called gadding and is also done by machinery. Two types 
of gadding machines are in common use, the one a diamond drill which 
bores a hole, and the other an impact drill which drives the hole in the 
ordinary manner. One of these, a special adaptation of the channelling 
machine, is used for the same purpose, shown in Fig. 9. It will be seen 
at once that the great advantage in the use of these machines lies in 
the fact that blocks of any desired size or shape can be taken out, and 
this too without the use of explosives. Where explosives, owing to local 




Fig. 6. — Ingersoll-Sergeant quarry bar drill. 



conditions, must be used, recourse is had to the Knox or some similai 
method of blasting in which direction is given to the force of the ex- 
plosion. 

Freed from the quarry bed, the stone is reduced to the required size 
and shape by means of hand implements or by machinery, as the case 
may be. In squaring a stone or roughly reducing it to the required 
shape, the common means is by plug and feather. A series of small 
holes, some three-fourths of an inch in diameter, and from 3 to 6 inches 
deep, according to the character of the stone, is driven along the line 
it is desired the stone shall break. Into each of these is then fitted two 



METHODS OF QUARRYING AND WORKING STONE. 



247 



wedge-shaped half-round pieces of soft iron, called feathers, and a small 
steel plug or wedge placed between. The workman then moves along 
this line striking each wedge in turn until they all bind alike and a 
sufficient strain produced to cause the blocks to fall apart. Until very 
recently these holes have been driven altogether by small hand drills 
and hammers. A pneumatic drill is now coming into use which bids 




Fig. 7. — Wardwell double-gauge channelling machine. 



fair to be very successful, Fig. 6 (see description of Mt. Airy quarries, 
p. 157). 

The surface of the stone is worked down by hand implements, such as 
the point, chisel, tooth chisel, pitching chisel, drove, axe or pean ham- 
mer, and the patent or bush hammer. Here, too, machinery is coming 
into use as in the pneumatic stone-surfacing machine shown in Fig. 10. 



248 



BUILDING AND ORNAMENTAL STONES OE NORTH CAROLINA. 



Soft stone, like the limestones, marbles and sandstones, are sawed by 
means of thin blades of soft steel fed with sand and water. The saws 
are usually set in gangs, perhaps a dozen in a single frame. Sand 







Fig. 8. — Ingersoll-Sergeant channelling machine. 



composed of crushed steel or chilled iron is sometimes used as the cut- 
ting medium, but is liable to rust and stain the stone. Lathes are used 
by some of the larger firms for turning columns. A monster machine 



METHODS OF QUARRYING AND WORKING STONE. 



249 



of this nature in use at the Bodwell Granite Quarries, Vinalhaven, 
Maine, weighs 135 tons and will take a column nearly 60 feet in length. 
Planers are used for producing flat surfaces, and especial forms of the 
machine, for moldings. 

REMARKS ON THE OPENING OF NEW QUARRIES. 

In the work of opening a new quarry many matters, in part foreseen, 
or, again, unforeseen, come up for consideration, and it will be well to 
dwell upon some of these in detail, even though our remarks may be 
in the nature of platitudes to the experienced quarrier. 




Fig. 9.— Ingersoll-Sergeant undercutting machine. 



Throughout the entire region south of the glaciated areas, the quarrier 
is confronted with a condition of affairs quite unknown to his more 
northern collaborator. Everywhere but on the steepest hillsides, or where 
exposed to the sweeping action of running water, his outcrops are ob- 
scured by ferruginous sands and clays of varying depth which often 
prove a serious handicap to quarry operations, involving no small initial 
outlay in the work of clearing or stripping, as it is commonly called. 
This material is largely residual, that is to say, it has resulted from the 
decomposition of the rock and the gradual accumulation of the less 



250 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

soluble portions on the surface. In the north the rocks likewise de- 
composed, but the debris was carried away by the ice sheet of the glacial 
epoch and the surface left hard and bare, ready for the quarrier. It 
is obvious that the southern quarrier is, at the outset, at a disadvantage ; 
but that there are compensating conditions, will be noted later. 

In opening a new quarry this residual mantle, or regolith, 1 as it has 
been called, must first be removed. Indeed, its partial removal is 
often rendered necessary before the extent and value of the quarry 
can be estimated, since it may so obscure all joints, flaws and natural 
defects of any kind as to make detailed observations impossible. The 
outcrops being visible, observations should be made as to the dip 
and strike of the beds, if the rock is sedimentary, their character, and 
the uniformity of the material. If the beds dip at a high angle, it 
follows that quarrying must be deep and expensive. 

It having been decided to open a quarry, the matter of disposal of 
waste or quarry dump and drainage should receive early attention. 
Particular pains should be taken to remove the debris to such a distance 
that it cannot possibly interfere with future development. The first 
opening, while it may be small, should be so made as to allow indefinite 
expansion, without doing any of the work for a second time. Disregard 
of this rule through thoughtlessness or a desire to make the quarry pay 
from the start has brought grief to many a promising undertaking. 

The drainage of a quarry is likewise an important matter. With 
quarries on a hillside, this is, as a rule, not difficult, but with those in 
a valley, as are the majority of the marble quarries of this State, pump- 
ing must often be resorted to, which, of course, adds to the cost of the 
output. 

Blasting, if resorted to at all during the preliminary work of quarry- 
ing, should be conducted with care, and particularly so in the case of 
tender rocks like the marbles. Careless work will result in the fracturing 
of the beds and the ruin of material. And here it may be said that too 
much care cannot be exercised to prevent, during the early development 
of a quarry, at least, the shipment of poor material. A bad reputation 
once gained is hard to live down. An insufficient amount of capital 
has often seduced operators into the shipment of surface material, full 
of bad joints, shaky, and it may be, discolored. The writer saw blocks 
of this nature loaded on the cars during the progress of this investiga- 
tion. To be sure, it was shipped as surface material, but, nevertheless, 
such is going to be seen and criticised by those who do not know all 

1 Rocks, Rockweathering, and Soils. 



METHODS OF QUARRYING AND WORKING STONE. 



251 



the conditions, and the reputation of the quarry will suffer in con- 
sequence. Competing quarriers will call attention to its defects, and in 
the end, economy of this nature will prove expensive. 

And a word regarding joints. It is common, near the surface, to find 
the rock broken into rectangular or polygonal blocks by sharp lines 
of division called joints. If present at all, such are very evident on 




Fig. 10. — Dallet pneumatic stone-surfacing machine. 



the surface, where they have been opened by the weather. As quarry- 
ing is carried on to depths beyond the reach of external heat or frost, 
these become less conspicuous and perhaps seemingly disappear alto- 
gether. Let not the quarrier deceive himself, however; they are there, 
and by close inspection may be discovered as merely sharp, straight lines, 
scarcely visible without a microscope. The old wounds have been par- 



252 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

tially healed by nature, and when freshly quarried such blocks seem 
sound and durable. But every one of these healed joints is a line of 
weakness and is going to manifest itself, if given time and proper con- 
ditions. In high-grade work no blocks should be used which show these 
joint lines, however closely they may seem to be cemented. Particularly 
should they be avoided in monumental work that is to be exposed to the 
weather from all sides. 

This jointing in rocks is a matter of interest for still other reasons 
than those noted above, since upon their character and abundance is 
largely dependent the size and shape of blocks that may be extracted. 
To illustrate this point more fully, (Pis. I and XIX) show a quarry 
in which the rock is transversed by a series of nearly horizontal joints, 
so strongly developed that very little energy is necessary to free the sheets 
one from another. Large, flat blocks, with beautifully fresh and even 
surfaces that can be cut up to any desired size — even to sizes too large 
for transportation — can thus be readily and cheaply obtained. Such 
quarries will furnish blocks for building, for monumental work, for 
monolithic columns, or for any purpose to which the rock is lithologically 
fitted. In other cases, where, it may be, these horizontal or bottom 
joints, as they are called, are equally well developed, there exists a second 
series of vertical joints running at right angles with the first. Such 
necessarily limit the length and breadth of the blocks obtainable. These 
quarries are best suited for the production of ordinary building and 
monumental material, and are ordinarily spoken of as block quarries in 
distinction from the sheet quarries above noted. 

It is obvious that in either of these cases the joints, provided not too 
near together and not discolored by sap, are of positive benefit to the 
quarries. It is posssible, however, that, owing to their abundance and 
to the angle at which they cut each other, they may be decidedly detri- 
mental or even ruin for architectural work what might otherwise be a 
good quarry. In the view shown in PL XXXII we have a quarry trans- 
versed by at least three sets of very conspicuous joints cutting each other 
at sharp and obtuse angles. The result is that natural blocks, though 
easily obtained, are of limited size and of such irregular shape that every 
one must be plugged or otherwise squared and dressed down before it is 
available. A quarry of this type cannot compete with such as are de- 
scribed above in the production of blocks of prescribed size — what are 
known commercially as dimension materials — but can be worked eco- 
nomically only for random rubble or for square blocks, when so sit- 



N. C. GEOLOGICAL SURVEY 



BULLETIN NO. 2. PLATE XXXII 




METHODS OF QUARRYING AND WORKING STONE. 



253 



uated as to have particularly favorable facilities in the way of extraction 
and transportation. 

In the preliminary work of opening a quarry the diamond drill may 
often be used to advantage, particularly in marble and sandstone beds. 
By means of this drill, cores can be obtained from any particular depth 
and an idea gained of the deep-lying material inaccessible by any natural 
exposures. Care must, however, be taken to ascertain the position of the 
beds thus bored into, or very misleading results may be secured. If the 
beds lie horizontally, as in (a) (see Fig. 11), it is obvious the cores 



■ ■ . . ■ . . ' 



ffi^ 



S 1 



1,1, I 



17 T 



T^ 



r~T 



1 I 1 




Fig. 11. — Drill holes in strata showing how erroneous ideas a thickness of bed ac- 
cepted by boring, a, Horizontal strata ; &, inclined strata ; c, vertical. 

obtained will give a very safe estimate of the thickness of the various beds, 
and the quality of the material. Where, however, the beds are inclined, 
as in (b), the cores will give a very exaggerated idea of the actual thick- 
ness, and when the beds stand vertical, as in (c), it may readily be seen 
results will be obtained that are wholly unreliable. In the case of granite 
rocks recourse to the diamond drill is rarely considered necessary, since 
long experience has shown that such rocks extend far beyond the limit of 
practical quarrying. 



18 



CHAPTER IX. 

THE WEATHEKING OF BUILDING STONES. 

It long since became evident that not all stones were equally durable 
when removed from the quarry and placed in the walls of a building. 
This is naturally a more conspicuous feature in the old than the new 
world, but nevertheless many of our older cities contain only too many 
illustrations of this failing. Many an expensive piece of stone carving, 
monument or stone front is to-day in a sad state of disintegration and 
decay, even though it may have been exposed for no longer a period than 
that covered by the life of its builder. The city of New York affords 
hundreds of illustrations of decayed house fronts, some of which are in so 
advanced a stage of disintegration as to make them actually unsightly. 

The causes of this disintegration are manifold, and have been elabo- 
rated elsewhere by Dr. Merrill. 1 The chief causes are the physical 
agencies of heat and cold, and the chemical agencies of solution in the 
water of rainfalls. These may be touched upon briefly here. 

It is a well known fact that under the influence of heat, stone like most 
other substances will expand, and contract under that of cold. A stone 
in the walls of a building, or lying upon the surface of the ground, will 
therefore be subject to the expansive action of the sun's heat during the 
day, and contraction by cold at night. The greater extremes of heat and 
cold the greater the expansion and contraction. At the extreme, the 
amount of change is slight for a single day, and not appreciable perhaps 
for a year, except to a trained observer. Nevertheless the daily repetition 
of the process in the extremes of night and day, of summer and winter, 
gradually weathers a stone on its immediate surface so that disintegration 
may result and the surface of a finely tool-dressed stone may become 
decidedly roughened within a comparatively few years. The freezing of 
water absorbed into the pores of a stone is a still more energetic source of 
disintegration; hence, stones capable of absorbing a considerable amount 
of water, more than 3 or 4 per cent by weight, are to be regarded as of 
doubtful durability in a climate where there is an abundant rainfall and 
where the temperature sinks frequently below the freezing point. 

1 See Rocks, Rockweathering, and Soils, Macmillan Co., N. Y., and Stones for Build- 
ing and Decoration, Wiley & Sons, N. Y. 



THE WEATHERING OF BUILDING STONES. 255 

Another cause of decay in a building stone is the solubility of certain of 
its constituents in the water of rainfalls. That any stone is really appre- 
ciably soluble in water may strike one as at first remarkable. Nevertheless 
it is true that many stones, and particularly limestones, are soluble in the 
water brought down by rainfalls, and sometimes so to a marked degree. 
The natural outcrops of beds of marble and limestone are often fluted and 
corroded in a marked degree by this means. Indeed the phenomena of a 
limestone cave is but an illustration of the solvent power of water on a 
larger scale. Stones which are of a uniform texture, as when composed 
of pure carbonate of lime, will often dissolve away so smoothly that the 
results are quite inconspicuous even after years of exposure. When, how- 
ever, a stone is of uneven texture, as in the case of a sandstone with a 
calcareous cement, the result may be more serious, particularly where the 
removal of this cement renders the stone more absorptive and hence more 
liable to the unfavorable influence of frost. 

A slight change in color is a by no means uncommon accompaniment of 
weathering. The more common change is one that takes place in rocks 
quarried from below the water level and in which a small amount of iron, 
presumably in solution, is in the form of a carbonate, sometimes as a 
sulphide in the form of finely disseminated iron pyrites. When the iron 
salt is evenly disseminated in small quantity, there may result a slight 
mellowing of the stone, i. e., the color changes from a dull gray or white 
to a slight buff tint. Where the iron is present as pyrite (or marcasite) 
in quantity, the weathering results in dull, dark and ferruginous blotches, 
which are quite unsightly. 

THE TESTING OF BUILDING STONE. 

In consideration of the facts above mentioned many tests have been 
devised, having in view the determination, in the laboratory, and within 
a comparatively brief period, the effect of prolonged exposure upon any 
stone it might be proposed to use. The tests most commonly resorted to 
are made with a view of ascertaining (1) the crushing strength, (2) the 
resistance to shearing forces, (3) the elasticity, (4) the ratio of expansion 
and contraction, (5) the absorptive power and resistance to freezing, (6) 

the fireproof properties, (7) corrodability, and (8) color changes. 

i 

Crushing Tests. — The first comprehensive and systematic series of 
tests of this nature in the United States were those made by General Q. 
A. G-ilmore 2 of the U. S. Army engineers, the results of which were pub- 

3 Ann. Rep. Chief of Engineers, U. S. A., 1875. 



256 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

lished in 1875. The methods employed have naturally been somewhat 
improved upon since Gilmore's time, but the changes are by no means 
radical. These and other tests are only touched upon somewhat briefly 
here, as the main purpose of this report is to describe in detail the build- 
ing and ornamental stones of the State. 

The common method employed in this test, then, consists in subjecting 
a carefully prepared cube of the stone to actual crushing, by means of 
specially designed machines. 3 Pressure is applied to the two opposite 
faces of the cube, the size of which, as experimented on by different indi- 
viduals, is somewhat variable; commonly either two or four inches on a 
side. The crushing strength as shown by the machine is usually given 
as a certain amount per square inch of crushing surface. Thus, if a cube 
whose crushing faces were exactly two inches on a side (comprising four 
square inches) is crushed under a weight of 60,000 pounds, its crushing 
weight would be given as 15,000 pounds per square inch. 

Many hundreds and even thousands of tests of this nature have from 
time to time been made. Indeed, it is the test which has received atten- 
tion above all others. The present writer has often stated his views 4 to 
the effect that the value of such tests is greatly overrated. To be sure, 
great strength is, to some extent, indicative of density, but it cannot 
always be accepted as indicating durability. It is not too much to say 
that a large portion of the tests made to-day are not worth their cost. 
This for the reason that any stone not so inherently weak as to be rejected 
on mere inspection will be found sufficiently strong for all practical pur- 
poses. The number of instances in which a stone in the walls of a 
building, arches and abutments of bridges, has crushed through actua] 
weakness are so few as to be ignored. Stones break through the pres- 
ence of flaws, or scale at the joints, from a lack of cement, but do not 
crush. Sufficient tests have already been made along the established 
lines to give us general principles, and for that reason few have been 
attempted in the present investigation. These few are described on 
page 236, and, as will be seen, were made to ascertain the strength of 
porous materials when dry, saturated with moisture, and after freezing. 

Architects and engineers still occasionally demand pressure tests, how- 
ever, and for the benefit of those who wish such made, it may be well to 
state that in the preparation of the cube to be tested care should be taken 
to select blocks free from defects and to have them reduced to the proper 

3 One of the best-known machines for this work is made by the Rhiele Bros., of Phila- 
delphia. • 

4 See Stones for Building and Decoration, Wiley & Sons, N. Y. 



THE WEATHERING OF BUILDING STONES. 



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258 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

size and shape through sawing and grinding rather than by chisel and 
hammer — a method liable to develop flaws. 

In order to illustrate the relative strength of stones of the different 
classes, the table on page 257 has been compiled from various sources. 

Shearing Tests. — The term shearing, as here used, includes strains due 
not only to pressure in one direction, but others due to pulling or thrust- 
ing in all directions up to those perpendicular to the first. It is a form 
of strain likely to be brought to bear on stone in many parts of a building 
and in bridges. The test, as performed by the army engineers, consists 
in subjecting prepared blocks or prisms supported at either end by blocks 
six inches apart, to a downward thrust applied by means of a plunger 
having a face five inches wide, there being a clearance space of half an 
inch between the sides of the plunger and the supporting blocks. The 
details of this and the other physical tests are given in the reports on the 
testing of metals, etc., by army engineers at the Watertown (Mass.) 
Arsenal, and need not be repeated here. 

Elasticity Tests. — These are of two kinds, (1) those made to ascertain 
the elasticity under compressive, and (2) those under transverse strains. 
The compressive elasticity test is made on prisms some 4 inches by 6 
inches by 24 inches, the loads being applied from the ends, i. e., in the 
direction of the longer axes, the problem being to ascertain not merely 
the amount of compression the stone will undergo, but also its power of 
regaining its first position and size when the pressure is removed. Ob- 
viously the amount of such compression is small, and can be measured 
only with very delicate instruments. It has been found in tests of this 
kind that the stones when thus treated shortly develop a permanent 
set; that is, would not quite recover from the compression during the 
period covered by the observations. 

The transverse elasticity test consists in bringing pressure to bear upon 
bars of stone supported at the ends (as in the shearing tests), except that 
the supports are farther apart and the pressure is applied at the middle. 
The amount of deflection or bending of the bar, without rupture, is of 
course dependent largely upon its elasticity, Ihe term modulus of rupture 
signifying the weight in pounds under which a bar one inch in diameter 
resting upon supports one inch apart will break, as calculated from the 
tests. 

Ratio of Expansion and Contraction. — Tests of this nature are of great 
interest and are extremely suggestive, as giving a clew to the weathering 



THE WEATHERING OE BUILDING STONES. 259 

qualities. Unfortunately, they are very delicate, requiring special appar- 
atus, and are expensive. But few such have been made. The method 
of testing consists in placing a carefully prepared and measured bar of 
stone in a vessel of water, of known temperature, and gradually raising 
the temperature to a point 100° C. above that at the beginning of the 
experiment. The gradual lengthening of the bar during the increase in 
temperature is noted, as is its gradual shortening on cooling. Though 
but few tests have been made, it has been shown that few if any rocks 
will, on cooling, quite regain their former dimensions. The difference, 
though measured it may be by but the ten-thousandths of an inch, is 
important since it means that cleavage planes in the individual minerals, 
and minute spaces between the minerals themselves have been developed, 
and that as a consequence the rock is not only weaker, but will prove more 
absorptive and more liable to injury from frost. 

Absorptive Power and Resistance to Freezing. — The amount of moist- 
ure any stone will absorb is dependent very largely upon the amount of 
space between the granules composing it. As a rule, crystalline rocks are 
not strongly absorptive, the individual granules being very closely com- 
pacted. But among the so-called fragmental rocks, such as the sand- 
stones, the granules are not in all cases closely compacted, and there may 
be thousands of minute interstitial cavities which will permit the absorp- 
tion of a very considerable amount of water. Such stones not merely 
give rise to damp walls, but are liable to disintegration through the 
freezing of this absorbed water. Figures showing the ratio of absorption, 
that is the relative proportion of weight which various stones will absorb, 
are given in the tables showing resistance to crushing, on page 257. 
Others, as made of North Carolina materials, are given on page 236. 
Tests to ascertain the ratio of absorption are made by simply immersing 
a prepared and weighed cube of stone in water and then boiling the 
water, or placing the vessel containing it under a bell jar and removing 
the air by an air-pump. This permits the water to enter all the pores. 
The cube is then removed and weighed after removing the excess of water 
on the outside by means of blotting paper. The increase in weight of the 
cube is of course the weight of the absorbed water and from it the per- 
centages are calculated. The resistance of the stone to the action of 
frost is ascertained by subjecting the cubes to repeated freezing and thaw- 
ing while in a saturated condition. At the conclusion of each period of 
thawing the loosened granules, if such there be, are brushed from the 
surface, and the cube weighed at the conclusion of the tests. The loss in 
weight shows then the resisting power. Enough tests of this nature have 



260 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

been made to show as a whole the sandstones are the most absorptive, and 
also that any stone that will absorb more than five per cent by weight of 
water needs to be regarded with suspicion until it shall have actually 
proven its value. It may be remarked, further, that pressure tests ap- 
plied to stones of the same kind in a dry and saturated condition, show 
a marked falling off in strength in the saturated cubes. This is shown 
in the table on page 236, in which cubes essentially two inches in diameter 
were experimented upon. 

Fire Tests. — It becomes occasionally desirable to learn the power of a 
stone to resist heat, or the rapid alterations of heat and cold. With the 
steady improvement in the methods of fireproof construction, such tests 
will become from year to year of less consequence and indeed are even now 
rarely resorted to. Tests that have thus far been made show that of all 
stone, certain of the siliceous sandstones and trappean rocks are most 
nearly fireproof, the coarse granites being the least so. The tests as 
performed are very simple and consist in merely heating a weighed block 
in a muffled furnace to a bright red heat, and then, while still hot, plung- 
ing it into a vessel of cold water. 

Corrodibility and Color Tests. — The test of corrodibility, or resistance 
to corrosion, is an important one where stone is to be subjected to the 
slightly acidulated water of rainfalls, as in manufacturing towns and 
cities. It is especially applicable to calcareous rocks, that is, to lime- 
stones and marbles, or sandstones containing a calcareous cement. Tests 
of this nature have, in years past, been made by Profs. A. W. Jackson, 
of Berkeley, California, and J. A. Dodge, of the University of Minnesota. 5 
For corrodibility, specimens of essentially the same size and weight are 
selected, dried and weighed. They are then suspended by strings in a 
vessel of water through which a stream of carbonic acid gas is kept con- 
stantly bubbling. This action is kept up for several weeks, when the 
specimens are removed, dried and weighed, the loss in weight indicating 
the corrodibility, i. e., the amount of material removed in solution by 
the carbonic acid water. As a rule in such tests the amount lost is very 
small ; in the case of siliceous rocks scarcely appreciable, but in calcareous 
rocks sometimes as much as one per cent. Tests for permanence of 
color, as performed by these same authorities, were as follows : Dried and 
weighed samples of the stone were placed on glass shelves in a porcelain 
dish containing strong hydrochloric (muriatic) acid. Close by were then 

5 See Final Rep. Geol. & Nat. Hist. Survey of Minnesota, Vol. I, and Ann. Rep. State 
Mineralogist of California for 1888. 



THE WEATHERING OF BUILDING STONES. 261 

placed open bottles one of which contained strong nitric acid and the 
other hydrochloric acid and a little manganese oxide, the whole being then 
covered by a bell glass. The chlorine and acid fumes rising and filling 
the chamber form an extremely corrosive and oxidizing mixture, and 
quickly attack any oxidizable compounds where such exist. The tests in 
cases of this kind should extend over a period of several weeks. 

Abrasive Tests. — Occasionally, when stone is to be used as in flooring, 
tiles, or street pavements, tests for determining the relative wearing 
qualities are desired. This is usually done by noting the rapidity of 
wearing down on a grinding bed. Such tests are of little value, however, 
except in the case of very homogeneous material. 

By far the most satisfactory way for ascertaining the power of any 
stone to withstand the weather is to study it in its natural outcrops, old 
quarry exposures, and in old buildings. This method has been pursued 
in the present investigation to the almost entire exclusion of all others. 
The climate of the State of North Carolina is sufficiently variable, so far 
as heat and cold are concerned, and there is a sufficiently heavy precipita- 
tion to try the stone severely. That they are affected by these influences 
is shown by the layers of soil, and rock residues that everywhere cover the 
rocks, except where removed by erosion. But the .havoc as seen here is 
that of ages untold in years ; we must accept the results guardedly, there- 
fore, and not too hastily condemn a rock because its outcrops are buried 
in its own debris. We want the comparative rate of decomposition rather 
than actual, knowing that the best is surely good enough, and that the 
worst may be safely rejected. 



APPENDIX. 

STONE FOE EOAD BUILDING. 

The demand for good roads, within recent years so enhanced through 
the introduction of the bicycle and automobile, has stimulated activity, 
not merely in road-building but in the study of road materials as well. 

The forms of pavement most used in this country, where traffic is too 
heavy for dirt roads, are those known as the Belgian block pavement and 
macadam. The first consists of roughly broken, but approximately rect- 
angular blocks of stone, some 4 inches by 6 inches by 10 inches in size, 
which are set in the roadbed in parallel rows, about an inch apart, the 
interstices being filled with sand and tar or asphalt. Such a road, while 
well suited for heavy traffic, has proven altogether too rough and noisy 
for residence streets and is too expensive for suburban and country roads. 

For these last situations, the form of pavement now most in favor is 
that known as macadam, named for its inventor, an English road engineer 
who brought the method of construction into prominence as long ago as 
1820. The utility of the invention, if such it can be called, is based upon 
the well-known property of stone, whereby broken particles will, when 
subjected to the friction of wheels and the pounding hoofs of animals, 
undergo a process of recementation which is due in part to the breaking 
away from the larger masses of fine angular particles, which gradually 
become compacted in their interstices, until the whole is converted into a 
moderately firm rock-mass again. Macadam is laid by different builders 
either with or without a layer or foundation of larger stones. Such a 
foundation, where used, is from 6 to 12 inches in thickness. Over 
this is laid from four to six inches of broken stone or road metal, as it is 
sometimes called. The size of this broken stone is dependent upon the 
amount of traffic and the quality of the material. The best size for hard 
stones, like the trap rock and close-grained granite, is given as from 
i to 1J inch cubes, while, in the softer stones, pieces from -J to 2\ inches 
are used. On roads for light driving it is customary to place a fine sur- 
facing of small stone, such as will pass through an inch mesh. Upon the 
character of this final surfacing is dependent, to a considerable extent, 
the quality of the road. 



APPENDIX. 263 

The chief essentials of stone to be used for macadam are hardness, 
toughness and cementing power. Concerning these qualities, the follow- 
ing is quoted : 

" By hardness is meant the power possessed by a rock to resist the wear- 
ing action caused by the abrasion of wheels and horses' feet. Toughness, as 
understood by road builders, is the adhesion between the crystal and fine 
particles of a rock, which gives it power to resist fracture when subjected 
to the blows of traffic. This important property, while distinct from hard- 
ness, is yet intimately associated with it, and can in a measure make up for 
a deficiency in hardness. Hardness, for instance, would be the resistance 
offered by a rock to the grinding of an emery wheel; toughness, the resist- 
ance to fracture when struck with a hammer. Cementing or binding power 
is the property possessed by the dust of a rock to act after wetting as a 
cement to the coarser fragments composing the road, binding them together 
and forming a smooth, impervious shell over the surface. Such a shell, 
formed by a rock of high cementing value, protects the underlying material 
from wear and acts as a cushion to the blows from horses' feet, and at the 
same time resists the waste of material caused by wind and rain, and pre- 
serves the foundation by shedding the surface water. Binding power is thus, 
probably, the most important property to be sought for in a road-building 
rock, as its presence is always necessary for the best results. The hardness 
and toughness of the binder surface more than of the rock itself represents 
the hardness and toughness of the road, for if the weight of traffic is suffi- 
cient to destroy the bond of cementation of the surface, the stones below 
are soon loosened and forced out of place. When there is an absence of 
binding material, which often occurs when the rock is too hard for the 
traffic to which it is subjected, the road soon loosens or ravels. 

" Experience shows that a rock possessing all three of the properties men- 
tioned in a high degree does not under all conditions make a good road 
material; on the contrary, under certain conditions it may be altogether 
unsuitable. As an illustration of this, if a country road or city park way, 
where only a light traffic prevails, were built of a very hard and tough rock 
with a high cementing value, neither the best, nor (if a softer rock were 
available) would the cheapest results be obtained. Such a rock would so 
effectively resist the wear of a light traffic that the amount of fine dust worn 
off would be carried away by wind and rain faster than it would be supplied 
by wear. Consequently, the binder supplied by wear would be insufficient, 
and if not supplied from some other source, the road would soon go to pieces. 
The first cost of such a rock would in most instances be greater than that of 
a softer one, and the necessary repairs resulting from its use would also be 
very expensive." 1 

Naturally, with material so weighty as stone, the cost of transportation 
is great. Hence, a large portion of the mass of any road must be of 
materials from nearby sources. It is with this fact in mind that the ob- 

1 See also, The Testing of Road Materials by Logan Waller Page, Bull. No. 79, Bureau 
of Chemistry, U. S. Dept. of Agriculture. 



264 BUILDING AND ORNAMENTAL STONES OF NORTH CAROLINA. 

servations here detailed have been made. Samples of material from 
quarries in operation as well as from outcrops which, from their locality 
seem promising, have been collected and submitted to tests at the Eoad 
Material Laboratory of the Department of Agriculture. The results are 
given in the accompanying table. 

In explanation of these results, it may be stated that, as a rule, a stone 
having a high or medium co- efficient of wear, a low percentage of wear, 
a high cementing value, and a low ratio of absorption will give the best 
results on the average road. 

It will be noticed that all the rocks listed are low in cementing value. 
Fortunately, this is a defect which can usually be easily remedied by 
adding a thin top dressing of some material having a high cementing 
value, such as clay, gravel, or some other rock high in this property. If 
clay is used, care must be taken not to add too much. In no case should 
a layer more than one-fourth of an inch thick be used. 



APPENDIX. 



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INDEX 



PAGE 

Abrasive tests of building stone 261 

Absorption of building stone 236, 257 

Granite of N. C. Granite Corporation, 259 

Relation of, to weathering 156 

Sandstone from W. Parsons' quarry . . 236 
Sandstone from Carrington-Gonella 

quarry . 236 

Adams Creek, granite near 96 

Advance, granite (porphyritic) near... 128 

Age relations of basic dikes 183 

Age of slates of the Carolina Igneous 

Belt 60 

Air compressed, use of in quarrying 

granite 158-160 

Alamance County, 

Basic igneous rocks 149-150 

Diabase 149, 150 

Diorite 149, 150 

Gabbro 149, 150 

Granites 61, 147-149 

Greenstones 149, 150 

Jointing of ' 149 

Tests for road metal 150, 265 

Texture of 149 

Uses of 149, 150 

Rocks of.- 147, 150 

Alexander County, 

Gneiss in 160, 161 

Granites in 152, 160, 161 

Rocks of 160, 161 

Alexander, serpentine near. . 213 

Alleghany County, granites of. 152 

Alleghany and Wilkes counties, granites 

of 161-163 

Rocks of 161-163 

Altamaha Granite area, granite of, 148, 149 

Pegmatite veins in 148 

Pyrite in 148 

Altamaha mills, granite near 148 

Amphibolite in Guilford County 144 

Amphibolite near Greensboro 144 

Andrews, marble near 197-200 

Anson County, 

Diabase dikes in 242 

Granite of 14, 15, 27 

Triassic sandstones in 219-223 

Diabase dikes in 219, 238-242 

Tests of for road metal 238, 265 

Aplite in granite of Raleigh City quarry, 

33, 180 

267 



PAGE 

Appalachian Mountains 3, 4 

Granite areas of 12, 64, 175 

Rocks of 164-174 

Ashe County, 

Gneiss in 174 

Granite in 174 

Asheville City quarry. 165 

Asheville gneiss area 165-167 

Quarries of 165-167 

Rocks of 165-167 

Asheville granite area ...164-167 

Augite syenite (See syenite). 
Balfour granite area, 

Gneiss of 169-170 

Balfour Quarry Company's quarries. 110-169 

Granite of 110 

Syenite of 94 

Ballew, marble near 200 

Barber Junction, 

Diorite near 91 

Granite near 120-122 

Granite dikes near 181 

Barium Springs granite area 89 

Mills Place 90 

Murdoch Place 90 

Wilhelm Place 90 

Barium Springs, 

Granite (porphyritic) near 89 

Mica-schist near 81 

Barton Creek, serpentine near 215 

Beaufort County, limestone in 205 

Beauty Falls, granite near 162 

Bell-Peysour opening, granite of 64 

Belmont, 

Granite near 65, 66 

Dike of quartz-porphyry in ... . 180, 181 

Quartz-porphyry at 71 

Belmont Springs, (see Belmont). 

Biddell quarry, granite at 84, 85 

Biltmore quarry, gneiss of 166 

Blakely quarry, granite at 78 

Blasting in opening new quarries. . .250-251 

Boilston, limestone near .208 

Bolans Creek, granite near 56 

Brasstown, marble near 200 

Breed quarry, granite at 82, 84 

porphyritic, inclusions of in normal 

granite 88 

texture of 83 

Brevard, limestone near 208 



268 



INDEX. 



PAGE 

Brockers Creek, granite near 56 

Brownstone (see Sandstone). 

Brown Summit granite area, granite of, 

136-138 

Brunswick County, limestone in 206 

Chemical analysis of 206 

Bryson City, 

Gneiss near 167, 168 

Granite near 167, 168 

Building stone, 

Abrasive tests of 261 

Absorption of 236, 257, 259 

Classification of 5 

Color tests of 260 

Contraction of 258, 259 

Corrodibility tests of 260 

Crushing strength of 255-257 

Elasticity of 258 

Essential qualities of 1 

accessibility 1 

color 1 

texture 1 

working qualities 2 

Expansion of 258, 259 

Fire tests of 260 

Shearing tests of 258 

Testing of 255-261 

Weathering of 254, 255, 261 

Varieties of 9 

Buildings constructed from granite of 

Balfour Quarry Co.'s quarries Ill 

N. C. Granite Corporation 157 

Buildings constructed from sandstone of 

Carrington-Gonella quarry 228 

W. A. Polk's quarry 221 

Buncombe County, 

Gneiss of 165 

Granite of 164, 165 

Limestone in 207 

Rocks of 164-167 

Schists of 164 

Serpentines in 212, 213 

Buncombe County quarry 166 

Gneiss of 166, 167 

Pegmatite veins in 166 

Pyrite in 167 

Burlington granite area, granite of, 146, 147 

Burlington, granite near 146 

Cabarrus County, 

Diabase dikes in 100 

Granite in 61, 77, 91 

Granite dikes in 181 

Granite (porphyritic) in 59, 95 

Granite porphyry in 97 

Rocks of 91, 92 

Syenite in 59 

Calcareous rocks 189, 190 

Quarrying of 190 

Structure of 189 

Uses of 190 



PAGE 

Varieties of 188 

Weathering of 189 

Caldwell County, 

Gneiss in 174 

Granite in 174 

Caldwell Place, granite in 70, 76, 77 

Carolina Igneous Belt, 

Dikes of 61, 58 

Age of 61 

Diorite of 59 

Granite areas of 61 

Granites of 57 

Veins in 58 

Granite (porphyritic) of 58, 59 

Resume of granites of 150-152 

Rocks of 12, 54, 58 

Age relations of 59 

Weathering of 61 

Slates of 60 

Age of 60 

Carrington-Gonella quarry, 227, 228, 235, 

236 

Equipment of 227 

Sandstone of 227, 228 

Absorption of 236 

Crushing strength of 228, 236 

Freezing tests on 235 

Carroll residence, granite near 51, 52 

Carthage, sandstone near 223-226 

Caswell County, granite in 61 

Castle Hayne, 

Limestone near 206 

Phosphate rock near 206 

Catawba County, limestone in 192 

Catawba River, 

Limestone near 209 

Marble near 202 

Cedar Rock, granite at 162 

Cementing materials of sandstones and 

quartzites 216 

Cementing value of stone for road metal, 

263, 265, 266 

Chapel Hill, 

Diorite near 55 

Granite near 56 

Sandstone near 231 

Chapel Hill granite area 56 

Charles Place, 

Diabase dikes near 135 

Granite on 134 

Charlotte City quarry, 

Equipment of 67 

Granite of 67 

Dikes in 68, 80 

Charlotte, dikes near 79, 80 

Charlotte granite area 67 

Caldwell Place 70 

Charlotte City quarry 67 

Dunn quarry 69 

Kirkpatrick opening 70 



INDEX. 



269 



PAGE 

Orders quarry 68 

Smith quarry 69 

Charlotte, 

Granite near, dike of quartz porphyry 

in 180, 181 

Quartz porphyry (leopardite) near.. 70-73 

Chatham County, 

Sandstone in 229, 230 

Triassic sandstone in 229, 230 

Diabase dikes in 238, 243 

Chemical analyses of 

Granite of Breed Quarry 84 

Granite (pink) from Dunns Moun- 
tain 106 

Granite from Mt. Airy 154, 155 

Granite of Raleigh City quarry 32 

Limestone in Brunswick County . . 206, 207 

Limestone near Fletcher 207 

Limestone near Southport 206 

Sandstone of W. A. Polk's quarry . . . 221 
Quartz-porphyry near Charlotte 74 

Cherokee County, 

Limestone in 192 

Marble in 192-200 

Classification of Building stones 5 

Clay in road building, use of 264 

Coastal plain region, granites of, 

14-27, 186, 187 
Table showing strike of joints in ... . 187 
Table showing strike of basic igneous 
dikes 186 

Color tests of building stone 260 

Concord City quarry, granite of 96 

Dike in 97 

Tests for road metal 96, 265 

Concord, 

Dikes near 58 

Diorite near 93, 99 

Granite dikes near 181 

Granite near 92, 93, 96 

Diabase dikes in 99 

Granite (porphyritic) near 95 

Granite porphyry near 97 

Syenite near 59, 93, 94 

Conrad Place, granite at 123-124 

Consolidated Granite Co.'s quarries, 

111, 120 

Granite of 112 

Pink granite of 112, 113 

Contentnea Creek, granite near 21 

Contentnea Creek area, granite of... 21, 22 

Feldspars of 22 

Tests of for road metal 23, 266 

Contraction and expansion of building 

stone 258, 259 

Relation of to weathering 258, 259 

Cooleemee Mills, 

Diabase dikes near 122 

Diorite near 120 

Granite near 118, 127, 128 

19 



PAGE 

Cook Gap, serpentine near 215 

Corrodibility tests of building stone .... 260 

Cotton mill outcrop, granite at 86 

Cow Rock Mountain, granite of 170 

Craven County, limestone in 206 

Cross Place, granite of 75 

Crowley's Creek, sandstone near 226 

Crushing strength of building stone 

. 255, 256 

Granite near Mt. Airy 155, 156 

Granite of N. C. Granite Corporation, 157 

Method of determining 256 

Sandstone of Carrington-Gonella 

quarry 228, 236 

Sandstone at W. Parsons quarry 236 

Table showing 257 

Crystalline rocks of North Carolina, 

Diabase dikes in 15 

Geographic distribution of 11, 12 

Field relations of 14 

Jointing in 15, 176, 177, 179 

Petrographic descriptions of 15 

Relation of dikes and veins of to 

jointing 176, 179 

Slickensides in 178 

Trend of dikes and veins penetrating, 

176, 185, 186, 187 
Culberson marble quarry, marble of, 

193, 194 

Cullowhee Gap, limestone near 208 

Cumnock, sandstone near 230 

Davidson County, 

Dikes of basic igneous rocks of.. 126, 127 

Granite dikes in 181 

Granite of 61, 122-126 

Granite (porphyritic) of 125, 126 

Rocks of 122-127 

Davidson, dikes near 80 

Davidson granite area 75 

Blakely quarry 78 

Caldwell Place 76 

Knox quarry 78 

Sloan Mill Place 77 

Davidson County 76-78 

Granite near 76-78 

Granite (porphyritic) near SO 

Davie County, 

Gabbro-diorite in 129-133 

Granite of 61, 127, 128 

Granite (porphyritic) in 58, 128 

Quarries of 127 

Rocks of 127-133 

Decomposition of granites 10 

Deep River, sandstone near 226, 229 

Devils Courthouse mountain, granite of, 170 

Diabase, color of 2 

Diabase dikes, (see Dikes). 

Diagram showing use of compressed air 

in quarrying granite 159 

Diamond Drill, use of 253 



270 



INDEX. 



PAGE 

Dikes, 

Aplite, in Raleigh City quarry. .179, 180 
Basic, 

Age relations of 183 

Intersecting granites of North Caro- 
lina, table of 179 

near High Point 126, 127 

near Lexington 126, 127 

near Thomasville 126, 127 

of Davidson County 126, 127 

Table showing strike of in Coastal 

Plain Region 186 

Table showing strike of in Piedmont 

Plateau 184 

Of Carolina Igneous Belt 58 

Age of 62 

Diabase of, 

Alamance County 149, 150 

Anson County 219, 238, 242 

Tests of for road metal in . . 238, 265 

Cabarrus County 91-100 

Charles Place 135 

Chatham County 238-243 

Concord 99 

Cooleemee Mills 122 

(in the) Crystalline rocks of N. C, 15 

Durham County 232, 239, 243 

Forsyth County 133, 136 

Gamble Place 139 

Guilford County 144, 145 

Tests of for road metal 144, 265 

Iredell County 91 

Jamestown 141 

Moore County 239-241 

Tests of for road metal. 237, 240, 266 
Oakdale cotton mill 141 

Tests of for road metal 141, 265 

Orange County 240-243 

Tests of for road metal 240, 266 

Rockingham County 20 

Rocky River 93, 99 

Rowan County 122 

Table of 184 

Steele's mill 20 

Tests of for road metal .... 238, 265 

Summerfield granite area , 138 

Wadesboro 21, 238, 242 

Winston-Salem 135, 136 

Diabase in 

Triassic sandstone 183, 237 

of North Carolina. 237-243 

Granite 

near Barber Junction 181 

in Cabarrus County 181 

near Concord . . . . 181 

in Davidson County 181 

in Diorite 181 

in Granite of Greystone quarries. . .180 

in Guilford County 181 

near High Point 181 



PAGE 

in Iredell County 180, 181 

near Lexington 181 

near Mt. Mourne 180 

in Porphyritic granite 87 

in Rowan County 181 

near Salisbury 181 

in Vance County 180 

Dikes and granites of the Piedmont 

Plateau Region 29 

Dikes in granite of 

Biddell quarry 85 

Charlotte City quarry 68, 80 

Concord City quarry 97 

near Davidson 76 

at Dunn quarry 69 

near Elm City .24, 25 

near Franklinton 41 

of Gaston County 66 

near Gastonia 67 

Greensboro City quarry 143 

of Hillsboro granite area 56 

near Louisburg 41, 42 

Test of for road metal 265 

of Louisburg area 41 

near Lowell Station 66 

along Mt. Pleasant road 98 

at New Greystone quarry 47 

near Rocky Mount 26 

at Old Greystone quarry 46 

at Snell opening 68 

on Tar River 26 

of Wyatt-Rolesville area 38 

Dikes, pegmatite 

in Guilford County 180 

in Iredell County 180 

in Raleigh City quarry 179 

Dikes of quartz porphyry in granite, 

near Belmont Springs 180, 181 

near Charlotte 180, 181 

of Mecklenburg County 180, 181 

Dikes near' (or in) 

Belmont 80 

Charlotte 79, 80 

Davidson 80 

Concord 58 

High Point 58 

Lexington 58 

Mecklenburg County 79 

Dikes, 

Relation of to jointing 181 

Strike of in Wadesboro-Rockingham 

area 20, 21 

Wadesboro-Rockingham area 20 

Dikes and veins, acid 179-182 

Dikes and veins 

of crystalline rocks of N. C, relation 

of to jointing 176, 179 

Penetrating crystalline rocks of N. C, 

176-188 
Trend of 176, 185-187 



INDEX. 



271 



PAGE 

Diorite of (or near) 

Alamance County 149, 150 

Barber Junction 91 

Carolina Igneous Belt 59 

Concord 93, 99 

Cooleemee Mills 120 

Chapel Hill 55 

Elmwood 91 

Faith 120 

Greensboro . . 143, 144 

Tests of for road metal 145, 265 

Granite dikes in 181 

Guilford County 144, 145 

Tests of for road metal 145, 265 

Guilford County quarry 143, 144 

Iredell County 91 

Josey-Boger Place 120 

Mt. Pleasant Road 98 

Orange County 55 

Raleigh City quarry 33, 34 

Rocky River 93 

Rowan County 59, 119, 120 

Woodleaf 59 

Dip of strata, influence of in opening 

new quarries 253 

Disintegration of granites 10 

Dodge, J. A., referred to 260 

Dolomite 188 

Color of 2, 3 

Definition of 186 

Distribution of 191-192 

Minerals of 188-190 

Uses of 189, 190 

Weathering of 188-190 

Working and quarrying of 190 

Drainage in opening new quarries 250 

Dubose quarry, gneiss of 167 

Duke quarry, sandstone of 233 

Dunn quarry, granite of, 12, 101, 104, 106 
108, 110, 111, 113, 114 

Dikes in 69 

Dunns Mountain granite area 100-114 

Balfour Granite Company's quarries, 

104, 110 
Consolidated Granite Company's quar- 
ries 104, 111 

Dunns Mountain granite quarries, 

104, 106 
McCanless quarry (see Dunns Moun- 
tain quarries). 
Phillips Mountain quarries ....104, 113 
Powler's Mountain quarries. .. .104, 114 
Quarries on north slope of Dunn's 

Mountain 104 

Rowan Granite Company's quarries, 

104, 108 
Dunns Mountain quarries, granite of, 

106-108 
Duplin County, limestone in 205 



PAGE 

Durham County, sandstone of, 232, 233, 

265, 266 
Diabase dikes in 232, 239-243 

Edgecombe County, granites of.. 14, 25, 27 

Elasticity of Building stones 258 

Elevation of Appalachian Mountain area, 

164 

Ellijay Creek, limestone on 208 

Elkin, granite near 162 

Elon College, granite near 148 

Elm City granite area, granite in. . . .23, 27 
Tests of for road metal 266 

Emmons, E., referred to 60, 205, 209 

Equipment of quarries in North Caro- 
lina 46, 48, 157, 196, 227 

Expansion and contraction of building 

stone 258, 259 

Faith, 

Diorite near 120 

Granite near 114 

Flat Rock (see Mt. Mourne exposure). 

Fletcher, lime kilns near 207 

limestone near 207, 208 

Forrest, C. N. referred to 206 

Forsyth County, 

Diabase dikes in 135, 136 

Granite of 61, 133-135 

Granite (porphyritic) of 58 

Rocks of 133-136 

Franklin County, granites in.... 25, 30, 38 

Franklinton, 

Granite near 38-41 

Granite (porphyritic) near 41 

Granite near, dikes in 41 

Freezing tests on sandstone of Carring- 

ton-Gonella quarry 235 

of W. Parsons quarry 235 

near Wadesboro 235, 236 

Freezing and thawing, effect of on sand- 
stone 234, 235 

Table of . . 236 

French Broad River, serpentine near, 

213, 214 

Gabbro, 

Alamance County 149, 150 

Color of 2 

Consolidated Granite Co.'s quarry, 

120, 122 

Guilford County 146, 147 

Tests of for road metal 147, 265 

Rowan County 120-122 

Gabbro-diorite, orbicular 129-133 

Color of 129 

Microscopical examination of .... 130-132 

Mineralogical composition of 130 

Quarry in 130 

Tetxure of 129 

Uses of 130 

Weathering of 129, 132 



272 



INDEX. 



PAGE 

Gamble Place, granite near 139, 140 

Diabase dikes in 140 

Porphyritic granite in 139 

Gaston County, 

Granite in 61, 62 

Dikes in 66 

Porphyritic granite in 58, 62 

Gastonia granite area 62 

Bell-Peysour openings 64 

Granite of 62, 63 

Hope quarry 65 

Jenkins quarry 65 

Gastonia, 

Dike in granite near 67 

Porphyritic granite near 62 

Gaston County, limestone in 192, 209 

Genth, F. A., referred to 71, 73 

Geographic description of granites of 

Piedmont Plateau Region 28 

Geologic description of granites of 

Coastal Plain Region 14 

Piedmont Plateau Region 28 

Geologic features, effect of upon rocks . . 6 
Georgia granite, granite of Mooresville 

area compared with 84 

Georgia marble compared with 

Mitchell County marble 204 

North Toe River marble 204 

Germantown, limestone near 209 

Gilmore, Gen. Q. A., referred to 255 

Glendon, sandstone near 226 

Gould's Fork, sandstone near 221, 222 

Governor's Creek, sandstone near 226 

Gneiss, 

Definition of 10 

Distribution of in North Carolina. ... 12 
Localities of 

Alexander County 160, 161 

Ashe County 174 

Asheville 165 

Asheville gneiss area 165-167 

Asheville City quarry 165 

Balfour granite area 169-170 

Tests of for road metal 177, 266 

Biltmore quarry 166 

Bryson City 167, 168 

Buncombe County 165-167 

Buncombe County quarry 166, 167 

Caldwell County 174 

Dubose quarry 167 

Hamilton quarry 165, 166 

Tests of for road metal 166, 265 

Henderson County 169, 170 

Hot Springs 171-174 

Howland quarry 167 

McDowell County . . 168, 169 

Madison County 171-174 

Marion gneiss area 168, 169 

Tests of for road metal 169, 266 

Maston place 135 



PAGE 

Mitchell County 174 

Montford quarry 166 

Rocky Face Mountain 160, 161 

Swain County 167, 168 

Taylorsville 160-161 

Watauga County 174 

Winston-Salem 135 

Quarries 165, 170 

Grain of stone 2 

Granite, 

Acid dikes on the veins intersecting, 

179-182 

Basic dikes intersecting 178, 179 

Chemical analysis of 155 

Pegmatite in 179-180 

Table of 179 

Color of 2, 10, 11 

Dikes (quartz porphyry) of Mecklen- 
burg County 180, 181 

Dikes (aplite) Raleigh City quarry.. 180 

and Dikes of Piedmont Plateau Region 29 
Granite 

Dikes, localities of 181 

Barber Junction 181 

Biddell quarry 85 

Cabarrus County 181 

Charlotte City quarry 68, 80 

Concord 181 

Concord City quarry 97 

Davidson 76 

Davidson County 187 

Dunn quarry 69 

Elm City area 24 

Franklinton 41 

Gamble Place 140 

Gaston County 140 

Gastonia 67 

Greensboro City quarry 143 

Greystone quarries 47, 180 

Guilford County 181 

Hillsboro granite area 56 

High Point 1S1 

Iredell County 181 

Jamestown 141 

Lexington 97, 181 

Louisburg 41, 42 

Lowell Station 66 

Mt. Mourne 180 

Mt. Pleasant Road 98 

Oakdale Cotton Mill 141 

Old Greystone quarry 46 

Rocky Mount 26 

Rocky River 99 

Rowan County 181 

Salisbury 181 

Snell opening 68 

Summerfield granite area 138 

Tar River granite area 26 

Wyatt-Rolesville area 38 

Dikes in diorite 181 



INDEX. 



273 



PAGE 

Grain of 11 

Hornblende in Kirkpatrick opening. . . 70 

Hornblende at Smith quarry 69 

Hydraulic pressure in quarrying. 157, 158 

Inclusions in, Caldwell Place 70 

Granite 

Localities of, 

Adams Creek 96 

Alamance County 61, 147-150 

Alexander County 152, 160-161 

Alleghany County 152 

Alleghany and Wilkes counties, 161-163 

Altamaha granite area 148, 149 

Pegmatic veins in 148 

Pyrite in 148 

Altamaha Mills 148 

Anson County 15, 27 

Appalachian Mountain area. . . .164-175 

Ashe County 174 

Asheville 164-167 

Balfour Quarry Company's quarries, 

110 

Buildings constructed from Ill 

Balfour granite area 169-170 

Barber Junction 120-122 

Beauty Palls Rock 162 

Bell-Peysour opening 64 

Belmont Springs 65, 66 

Dike of quartz-porphyry in. .180, 181 

Biddell quarry 84, 85 

Blakely quarry 78 

Bolans Creek 56 

Breed quarry 82, 83 

Chemical analysis of 84 

Brockers Creek 57 

Brown Summit granite area 136-138 

Pegmatites in 137 

Bryson City 167, 168 

Buncombe County 164-167 

Burlington 147 

Burlington granite area 147 

Cabarrus County 61, 77, 91, 95 

Caldwell County 174 

Caldwell Place 70, 76, 77 

Carolina Igneous Belt area 58, 61 

Carroll residence 51, 52 

Caswell County 61 

Cedar Rock 162 

Chapel Hill 55 

Chapel Hill granite area 56 

Charles Place 134 

Charlotte City quarry 67, 68 

Coastal Plain Region 12, 27 

Accessibility of 27 

Geographical description of 14 

Geological description of 14 

Table showing strike of schist of, 187 

Concord 92, 93, 96 

Concord City quarry 96, 97 

Conrad Place 123, 124 



PAGE 

Consolidated Granite Co.'s quarries, 

111-113 
Contentnea Creek area 21-23 

Feldspars in 22 

Tests of for road metal 22, 266 

Cooleemee Mills 118, 127, 128 

Cotton mill outcrop 86 

Cow Rock Mountain 170 

Cross Place 75 

Davidson area 67, 75, 77, 78, 79 

Davidson 61, 76, 78 

Davidson County 61, 122-126 

Davie County 61, 127, 128 

Devils Courthouse Mountain 170 

Dubose quarry 167 

Dunn quarry 69 

Dunns Mountain area 101-104 

Pink, relation of to gray granite, 

102, 103 
Dunns Mountain granite quarries, 

106-108 
Dunns Mountain, north slope of 

104-106 

Chemical analysis of 106 

Edgecombe County 25, 27 

Elkin . 162 

Elm City area 21-24, 27 

Tests of for road metal 266 

Elon College 148 

Faith 114 

Forsyth County 61, 133, 135 

Franklin 170, 171 

Franklin County 25, 30, 38 

Friendship granite area 136, 140 

Fritts Place 124 

Gamble Place 139, 140 

Gaston County 61, 62 

Gastonia granite area 62, 63 

Granite Quarry Station 110 

Granville County 30, 53 

Grays Mill. 138 

Greensboro City quarry 142, 143 

Tests of for road metal 143, 265 

Greensboro granite area 142, 143 

Greystone Granite & Construction 

Co.'s quarry . 48, 49 

Guilford County 61, 136 

Hairston Place 127, 128 

Halifax County 25 

Hall Place 147, 148 

Haw River 148, 149 

Henderson 52 

Henderson County 169, 170 

Highlands 170, 171 

High Point 142 

Hillsboro granite area 55, 56 

Hitchcock Creek 16 

Hogback Mountain 170 

Hope quarry 65, 66 

Hoskins Place 138, 139 



274 



INDEX. 



PAGE 

Hot Springs 164, 171-174 

Hot Springs granite area 171-174 

Howland quarry 167 

Iredell County 61, 80, 150, 180 

Jamestown 140, 141 

Jamestown granite area 140-142 

Jenkins quarry 65 

Josey-Boger property 116, 117 

Kirkpatrick Opening 70 

Knox quarry 78 

Lewis Place 35 

Lexington 123-126 

Lilesville 16, 17, 20 

Little Stone Mountain 162 

Louisburg granite area 38, 39, 40 

Pegmatite in . . 40 

.McGrady quarry . .140 

McNeely quarry 81, 82, 84 

Madison County 164, 171-174 

Mecklenburg County 61, 67, 77 

Middleburg granite area 50, 51 

Mills Place 90 

Mitchell County 174 

Moccasin 39 

Modlin quarry 142 

Mooresville area 80, 81 

Compared with Georgia granites. 84 

Morning Glade Church area 67, 74 

Mt. Airy 152-160 

Buildings constructed from 157 

Methods of quarrying. .157-160, 244 

Tests of for road metal 157, 266 

Mt. Pleasant Road 98 

Murdoch Place 90 

Nash County 25, 27 

New Greystone qv.arry 47, 48 

North Carolina Granite Corporation 

152-157 

Absorption of 156 

Buildings constructed from 157 

Methods of quarrying 157, 160 

Tests of for road metal 157, 266 

Weathering of 152 

Norwood Farm 44 

Oakdale Cotton Mill 141, 142 

Tests of for road metal 141, 265 

Old Greystone quarry 45, 46, 47 

Orange County 55 

Orders quarry 68 

Ossipee Mills 148 

Oxford 53 

Paschal Farm 44 

Penitentiary quarry 34, 35 

Phillips Mountain 102 

Phillips Mountain quarries. . .113, 114 

Piedmont Plateau Region 28-53, 185 

Powlers Mountain quarries. ... 114-116 

Pyrite in 116 

Raleigh area 30-32 

Raleigh City quarry 30, 179, 180 



PAGE 

Aplite in 32, 180 

Faulting in 33 

Minerals associated with... 179, 180 

Pegmatite in 33, 179, 180 

Redf ord Farm 37 

Pegmatite in 37 

Pyrite in 37 

Reedy Fork 148 

Rhodes Farm 64 

Richmond County 15, 27 

Rockingham 14 

Rocky Face Mountain granite area, 

160, 161 
Compared with Georgia granite.. 161 

Rocky Mount 25, 26, 262 

Rocky River 77 

Rogers Branch 137, 138 

Rolesville 36, 37 

Pyrite in 37 

Rowan County .... 12, 61, 100-119, 150 
Pink, relation of to gray granite, 

102, 103 
Rowan Granite Co.'s quarries . . 108, 109 

Salisbury 100-119, 150 

Seaboard Air Line Railway quarry, 

49, 50 

Sheep Cliff Mountain 170 

Sink Place 125 

Sloan Mill Place 77, 78 

Smith quarry 69, 70 

Pyrite in 69 

Snell opening 68 

Spring Hope 25 

Statesville 90 

Steele's Mill 16 

Stewart Place 92 

Stone Mountain granite area. . 161-163 

Summerfleld granite area 13S-140 

Surry County 12, 152-160 

Swain County 167, 168 

Tar River 25, 26, 38 

Teeders Place 92 

Toxaway Lake 171 

Toxaway Mountain 170 

Transylvania, Jackson and Macon 

Counties 170-171 

Trap Hill 162 

Vance County 12, 30, 44, 45, 52, 180 

Wadesboro 15, 16 

Wadesboro-Rockingham area, 15, 16, 
18, 19, 27 

Pyrite in 18 

Wake County 30, 39 

Walker Place 136, 137 

Warren County 30, 42 

Warren Plains granite area 43 

Warrenton granite area 42 

Watauga County 174 

Pyrite in 18 

Whiteside Mountain 170 



INDEX. 



275 



PAGE 

Wiggins Mill 21 

Wilhelm Place 90 

Wilkes County 152 

Wilkes and Alleghany counties, 161-163 

Wilkesboro 161-163 

Williamsboro 53 

Wilson 21, 27 

Wise 44 

Wolf Rock 162 

Woodleaf granite area 117, 118 

Pyrite in 117 

Wyatt Station 36 

Pegmatite in 36 

Wyatt-Rolesville granite area 36 

Yadkin River 127, 128 

Granite, 

Methods of quarrying 244 

Microscopical features of 9 

Minerals of 9 

Porphyritic, 
Localities of, 

Advance 58, 128 

Barium Springs 80, 89 

Breed Quarry 88 

Relation of to normal gneiss . . 187 

Cabarrus County 59, 95 

Carolina Igneous Belt 58, 59 

Concord . ■ 59, 95, 93 

Davie County 58, 126 

Davidson County 80, 126, 128 

Forsyth County 58 

Gamble Place 139 

Gaston County 62 

Gastonia granite area 58, 62 

Iredell County 58, 80 

Lexington 125, 126 

Landers 95 

Mecklenburg County 80 

Mooresville 58, 80, 86, 87 

Mooresville area 88 

Murdoch Place 90 

Nissen Place 134, 135 

Rowan County 58 

Salisbury graphitic granite area, 

118, 119 

Schulenberger's Branch 95 

Statesville 80 

Summerfield granite area. . . .138-140 
Winston-Salem granite area. .133-135 
Porphyritic, 

Microscopical examination of.. 115, 116 
Mineralogical composition of . . . .86, 87 
Porphyritic phenocrysts of 17, 86, 87, 
89, 95, 119, 126, 128, 133, 135 
Quarries, 

Ashevville 164, 165 

Balfour granite area 169-170 

Carroll Residence 51 

Greystone 45 

Middleburg 50, 51 



PAGE 

Mt. Airy 153-160 

Northeastern Carolina Granite 

Belt 30 

Raleigh 30 

Vance County 44 

Greystone granite area 45 

Henderson granite area 52 

Middleburg granite area 52 

Porphyry, 

Cabarrus County 97 

Rift of 11 

Segregations of 

Kirkpatrick opening 70 

Mt. Airy 154 

North Carolina Granite Corpora- 
tion 153 

Smith quarry 69 

Stone Mountain granite area 162 

Strength of 11 

Structure of 9 

Uses of. 11 

Weathering of 10 

Western Piedmont Gneiss and Gran- 
ite Belt 152-163 

Working and quarrying of 11 

Granite-Gneiss Belt of Western Piedmont 

region 152-163 

Granville County, granites in 30, 53 

Gray's Mill, granite near 138 

Gray, R. P., referred to 155, 156 

Greensboro, amphibolite near 144 

Greensboro City quarry, 

Dikes in granite of 143 

Granite of 142, 143 

Tests of granite for road metal 143 

Greensboro, 

Diabase near 144, 145 

Tests for road metal of 144, 265 

Diorite near 143-145 

Tests for road metal of 145, 265 

Gabbro near 146, 147 

Tests for road metal of 147, 265 

Greenstone near 144 

Greenstone, 

Alamance County 149, 150 

Tests of for road metal 150, 265 

Greensboro 144 

Guilford County 144 

Greystone, 

Granite at 12 

Quarries near 30 

Gryestone granite area quarries 44 

Greystone Granite & Construction 

Co.'s quarry 48 

New Greystone quarry 47 

Old Greystone quarry 46 

Seaboard Air Line Railway quarry ... 49 
Greystone granite area, 

Granite dikes in granite of 180 

Quarries in 45 



276 



INDEX. 



PAGE 

Greystone Granite & Construction Co.'s 

quarry 48, 49 

Guilford County, 

Amphibolite in 144 

Basic igneous rocks in 144-147 

Diabase in 144, 145, 265 

Diorite in 144, 145, 265 

Gabbro in 146, 147, 265 

Granite in 61 

Brown Summit granite area. . . .136-138 

Friendship granite area 136, 140 

Greensboro granite area. .136, 142-144 
Jamestown granite area.. 136, 140-142 
Summerfield granite area, 136, 138-142 

Granite dikes in 181 

Greenstone in 144 

Pegmatite dikes in 180 

Pegmatite veins in 180 

Rocks of 136-147 

Guilford County quarry, diorite of. 143, 144 
Hairston Plantation, 

Gabbro-diorite near 129-133 

Granite of 127, 128 

Quarries near 127 

Halifax County, granite in 25 

Hall Place, granite at 147, 148 

Hamilton quarry 165 

Gneiss of 165, 166 

Test of gneiss of for road metal, 

166, 265 
Hammonds, Frank, quarry, sandstone at, 

221 

Hanna, Geo. B., referred to 13, 59 

Hardness of stone for road building. .263, 

265, 266 

Haskett quarry, limestone near 209 

Haw River, granite near 148, 149 

Howland quarry, gneiss of 167 

Hays, J. F., farm, marble on 197 

Heat and cold upon weathering of build- 
ing stones, effect of 254-255 

Henderson, granite near 52 

Henderson County, 

Gneiss and Granite of 169, 170 

Limestone in 208 

Quarries in 169, 170 

Rocks of . 169, 170 

Hendersonville, limestone near 208 

Hewitts, marble near 200 

Hickerson, C. N., farm, marble on 198 

Highlands, granite near 170, 171 

High Point, 

Dikes of basic igneous rocks near, 58, 

126, 127 

Granite near 142 

Granite dikes near 181 

Hillsboro granite area 55, 56 

Hitchcocks Creek, granite on 16 

Hiwassee River, marble near 200 

Hogback Mountain, granite of 170 



PAGE 

Holmes, J. A., referred to 28, 164 

Hope quarry, granite of 65, 66 

Hope River, sandstone near 231 

Horton's quarry, sandstone at 222, 223 

Hoskins Place, granite near 138 

Hot Springs, 

Gneiss near 171-174 

Limestone near 209 

Test of for road metal 209, 266 

Unakite near 164, 172-174 

Hot Springs granite area, 

Granite of 164, 171-174 

Syenite of 172 

Howland quarry 165 

Gneiss of 167 

Tests of for road metal 167 

Hunter, C. L., referred to 70 

Hydraulic pressure used in quarrying 

granite 157, 158 

Inclusions in granite at Caldwell place. 70 
Tnclusions of porphyritic granite in nor- 
mal granite 87 

Iredell County, 

Diabase dikes in 91 

Diorite in 91 

Granite in 61, 80 

Granite (porphyritic) in 58, 80 

Granite dikes in 180, 181 

Mica-schist near 81 

Pegmatite dikes in 180 

Ivy River, serpentine near 215 

Jackson, A. W., referred to 260 

Jackson, Transylvania and Macou 

counties 170, 171 

Granite of 170, 171 

Rocks of 170, 171 

Jamestown granite area, granite of, 140-142 
Jamestown, diabase dike in granite near, 

141 

Jenkins quarry, granite of 65 

Johnson quarry (See Breed quarry). 
Jointing 

in Crystalline rocks 15 

in Granite of Piedmont Plateau Re- 
gion, table showing strike of 185 

Relation to the opening of new quar- 
ries 251, 252 

Relation of to dikes 181, 237, 243 

in sandstones and quartzites 219 

Jointing (see under Granite, Marble, 

Sandstone, etc.) 
Josey-Boger property, 

Diorite near 120 

Granite of 116, 117 

Keith, Arthur, referred to, 13, 164, 171, 174 

Kerr, W. C, referred to 12, 13, 28, 

29, 32, 60. 

Kerr, W. H., referred to 13 

Killetts Creek, sandstone near 224 

Kinsey quarry, marble of 194 



INDEX. 



OT 



PAGE 

Kirkpatrick opening, hornblende granite 

in 70 

Knox quarry, granite from 78 

Landers, porphyritic granite at 95 

Laurel Creek, limestone on 209 

Leopardite (see Quartz-porphyry). 

Lewis, J. V., referred to 13, 71, 84, 106, 

155, 202, 210 
Lewis Place, description of granite from 35 
Lexington, 

Basic igneous rocks near 126, 127 

Dikes near 58 

Gabbro-diorite near '. 129-133 

Granite area 123 

Conrad Place 123, 124 

Fritts Place 124 

Sink Place 125 

Granite near 123-126 

Granite dikes near 181 

Granite, porphyritic near 125, 126 

Lilesville, granite near 16, 17 

Limestone, 

Areas of in North Carolina 205, 207 

Color of 2, 3, 188 

Definition of 188 

Distribution of 191, 192 

Lenses of in schists 207 

Localities of 

Beaufort County 206 

Boilston 208 

Brevard 208 

Brunswick County 206 

Catawba County 192 

Catawba River 202, 209 

Castle Hayne 206 

Cherokee County 192 

Craven County 206 

Cullowhee Gap 208 

Duplin County 206 

Ellijay Creek 208 

Fletcher 207, 208 

Gaston County 192, 209 

Germantown 209 

Haskett quarry 209 

Henderson County 208 

Hendersonville 208 

Hot Springs 209 

Tests of for road metal 266 

Laurel Creek 209 

Lincoln County 192 

Macon County. . 208 

Madison County 209 

Marion 209 

McDowell County 202, 209 

Neuse River .206 

Newbern 206 

New Hanover County 205, 206 

North Carolina, 

Piedmont and Mountain areas, 

207, 209 



PAGE 

Southeastern area 205, 207 

North Cove 202 

Onslow County 206 

Pender County 206 

Southport 206 

Stokes County 209 

Swain County 192 

Toxaway River 208 

Transylvania County 208 

Trent River 206 

Wilmington 205, 206 

Woodfin quarry 208 

Woodlawn 209 

Methods of quarrying 190, 244 

Mineralogical composition of .... 188-190 

Texture of 188 

Uses of 189, 190 

Varieties of 188 

Weathering of 188-190 

Lime, limestone suitable for 207 

Lincoln County, limestone in 192 

Linehan & Sons, T., referred to 46 

Linehan quarry, sandstone of 219, 220 

Little Pine Creek, serpentine near 214 

Little Stone Mountain, granite of 162 

Louisburg granite area 38, 42 

Pegmatite in 40 

Lowell Station, dikes in granite near. . . 66 

Macon County, limestone in 208 

Macon, Transylvania and Jackson coun- 
ties, granite of 170-171 

Macadam, stone for 262-266 

McDowell County, 

Gneiss of 168, 169 

Limestone in 202, 209 

Marble of 202 

Quarries in 168 

Rocks of . . 168, 169 

McGalliard quarry (see Consolidated 
Granite Co.'s quarry). 

McGrady quarry, granite of 140 

McLendon's Creek, sandstone near, 225, 226 

McNeely quarry, granite of 81 

McNeill, A. H., farm, sandstone on 224 

Machinery, use of in quarrying and 

working stone 244, 253 

Madison County, 

Gneiss of 171-174 

Granite of 164, 171-174 

Limestone in 209 

Rocks of 164, 171-174 

Serpentine in 214 

Syenites of 172 

Unakite of 164, 172-174 

Marble, 

Color of 188 

Definition of 5, 188 

Distribution of 191-192 

Localities of 188-206 

Andrews 197-200 



278 



INDEX. 



PAGE 

Ballew 200 

Brantown 200 

Brasstown 200 

Catawba River 202 

Cherokee County 192 

Culberson Quarry 193 

Hays Farm 197 

Hewitts 200, 201 

Hiawassee River 200 

Hickerson's Farm 198 

Kinsey quarry 194 

Marble Station 197 

Marble 204 

Mitchell County 203 

McDowell County. 202 

Pyrite in 202 

Murphy 192-195 

Nantahala River 200-202 

National Marble Co.'s quarry 195 

North Toe River 205 

North Cove 202 

Notteley River 192 

Peachtree Creek 200 

Red Marble Gap 200 

Regal 195 

Sinkhole Creek 203 

Swain County 200-202 

Valley River 192, 197, 198 

Woodlawn 202 

Methods of quarrying 244 

Mineralogical composition of.. 192, 193, 
195, 200, 201 

Minerals of 188, 189, 190 

Origin of 5, 6 

Pegmatite dike in 204 

Quarries of 192-204 

Texture of 188 

Uses of 189, 190 

Varieties of 188 

Weathering of 188, 190 

Marion gneiss area 168, 169 

Quarries in 168 

Tests of for road metal 169, 266 

Markets for building stones, position of 

N. C. in relation to 8 

Marshall, serpentine near 214 

Marston, A., referred to 234 

Maston Place, gneiss near 135 

Merrill, Geo. P., referred to.. 5, 13, 18, 71, 

221, 254 
Mecklenburg County, 

Dikes in 79 

Granite in 61, 67, 77 

Porphyritic granite 80 

Quartz-porphyry in 70, 71 

Rocks of „ 67 

Mica-schist, 

near Barium Springs 81 

in Iredell County 81 

near Statesville 81, 91 



PAGE 

Middleburg Granite area 12, 50, 51 

Mills Place, granite at 90 

Mineralogical composition of 

Dolomite 188-190 

Granite 9, 22 

Marble 188-190 

Minerals associated with pegmatite 

dikes 179, 180 

Minnesota Geological Survey referred to, 

260 
Mitchell County, 

Gneiss in 174 

Granite in 174 

Marble in 203-205 

Pegmatitic dike in 204 

Moccasin Creek, granite near 39 

Modlin quarry, granite of 142 

Monf ord quarry, gneiss of 166 

Moore County, 

Diabase dikes in 223, 239, 240 

Test of for road metal 266 

Quarries in 223-229 

Sandstone in 223-229 

Mooresville area, 

Even-grained granite of 81 

Granite of 80, 84, 88 

Porphyritic granite of 86 

Mooresville, 

Granite near 80 

Porphyritic granite near 58, 80 

Sandstone near 231 

Morning Glade Church area 74, 75 

The Cross Place 75 

Mount Mourne, 

Granite dikes in granite near 180 

Porphyritic granite near 58, 87 

Mt. Pleasant road, 

Diorite near 98 

Granite along 98 

Mt. Airy, 

Granite near 12, 152-160 

Compared with Georgia granite . . . . 161 

Quarries at 152-160 

Murdoch Place, granite at 90 

Murphy, marble near 192, 195 

Nantahala River, marble near 200-202 

Nash County, granite in 14, 25, 27 

National Marble Co.'s quarry 195 

Neuse River, limestone near 206 

Newbern, limestone near 206 

New Greystone quarry 47, 48 

New Hanover County, limestone in. 205, 206 

Nissen Place, porphyritic granite on 134 

Nitze, H. B. C, referred to, 13, 26, 54, 59, 

60, 100, 123 
North Carolina 

Diabase dikes in 237-243 

Gneisses in 12 

Map showing distribution of 30 

Granites in 11-175 






INDEX. 



279 



PAGE 

Map showing distribution of 30 

Limestone areas of 192, 205, 207, 209 

Marble deposits of 192-205 

Market for building stones of 4, 8 

Rocks for road metal in 265-266 

Sandstone of 237 

Serpentines of 212 

Surface features of 3, 4 

Triassic sandstones of 237-243 

Tests of for road metal 266 

North Carolina Granite Corporation 

quarries 153, 154-160 

Test of for road metal 266 

North Cove, 

Limestone near 202 

Marble near 202 

Northeastern Carolina Granite Belt, 

granites of . . . 29, 53 

Quarries in 30 

Resume of 53 

North Toe River, marble near. ... .203-205 

Norwood Farm, granite on 44 

Notteley River, marble near 192 

Oakdale Cotton Mill, granite near. .141, 142 

Diabase dike in 141 

Test of for road metal 141, 265 

Old Greystone quarry, 

Equipment of. 46 

Granite at 47 

Dikes in . . „ 46 

Olivette Station, serpentine near 213 

Onslow County, limestone in 205 

Orange County, 

Diabase dikes in 240-243 

Test of for road metal 240, 286 

Diorite in 55 

Granite in. 55 

Sandstone in 230, 231 

Orbicular granite (see Gabbro-diorite). 

Orders quarry, granite at 68 

Origin of 

Calcareous rocks 5 

Fragmental rocks 5 

Marble 5, 6 

Serpentines 210 

Siliceous crystalline rocks 5 

Slates 6 

Ossipee Mills, granite near 148 

Overlook Park, quarries near 167 

Oxford, granite near 53 

Page, Logan Waller, referred to 263 

Parsons W., quarry, sandstone at 222 

Physical tests of 235, 236 

Paschal Farm, granite on 44 

Peach tree Creek, marble near 200 

Pegmatite dikes 179, 180 

Color of „ 179, 180 

in Granite 

of Altamaha granite area 148 

of Brown Summit area 137 



PAGE 

of Greystone granite area 148 

of Louisburg granite area 1 40 

of Raleigh City quarry 179 

from Redford Farm 37 

near Wyatt Station 36 

in Buncombe County 166 

in Guilford County 180 

in Iredell County 180 

in Marble 204 

in Mitchell County 204 

in Wake County ISO 

Minerals associated with 179, 180 

Texture of 179, 180 

Pender County, limestone in 205 

Penitentiary quarry, granite of 34, 35 

Phenocrysts (see under Granite). 
Phillips Mountain quarries, granite of, 

102, 113, 114 

Phosphate rock near Castle Hayne 206 

Piedmont Plateau 3, 28 

Areas of granite in 12 

Map showing distribution of 12 

Basic igneous rocks in 184 

Dikes in 28, 29 

Polk, W- A - quarry, sandstone of.. 220, 221 
Porphyritic granite (see under Granite). 

Powlers Mountain quarries 114 

Granite of 115, 116 

Pratt, Joseph Hyde, referred to. 13, 207, 210 
Pyrite, relation to weathering of build- 
ing stones 255 

Quarries, see under Granite, Marble, 

Sandstone and counties. 
Quarries, 

in Granite 21-174 

in Limestone 207-208 

in Marble 192-205 

in Sandstone 223 

Opening new 249-253 

Blasting in 250, 251 

Use of diamond drill in 253 

Quarrying 

in Appalachian Mountains 164 

Method of 

Calcareous rocks 190 

Dolomite , 190 

Freestone 218 

Granite 157, 244 

Limestone 190, 244 

Marble 244, 253 

Sandstone 244, 253 

Quartzites (see Sandstones). 
Quartz-porphyry, dike of in granite near 

Belmont Springs ISO, 181 

Quartz-porphyry, 

at Belmont Springs 71 

near Charlotte 70 

in Mecklenburg County 71 

Quartz veins in granite 181 



280 



INDEX. 



PAGE 

Rackle and Lawrence quarry, sandstone 

in 228, 229 

Rainfall, effect of upon weathering of 

building stone 255 

Raleigh City quarry, 

Aplite in 33, 180 

Diorite in 33, 34 

Granite of 180 

Chemical analysis of 32 

Pegmatite dikes in 179 

Raleigh Granite area, quarries in 30 

Raleigh, 

Quarries near 30, 31 

Serpentine near 215 

Reddies River, serpentine near 214 

Red Marble Gap, marble near 200 

Redford Farm, granite from 37 

Reedy Fork, granite near 148 

Reems Creek, serpentine near 213 

Regal, marble near 195 

Reid quarry (see Concord City quarry). 

Rhodes Farm, granite on 64 

Rhyolite (see Quartz-porphyry). 

Richmond County, granite in.... 14, 15, 27 

Rift of 

granites 11 

stone 2 

Rockingham, dike in 20 

Rocks, see under 

Diabase. 

Diorite. 

Dolomite. 

Freestone. 

Gabbro. 

Gneiss. 

Granite. 

Granite-porphyry. 

Leopardite. 

Limestone. 

Marble. 

Orbicular-diorite. 

Pegmatite. 

Quartzite. 

Sandstone. 

Serpentine. 

Syenite. 

Rock phosphate near Castle Hayne 206 

Rocky-Face Mountain, gneiss of... 160, 161 
Rocky Mount, granite near 25 

Dikes in 26 

Rocky River area, granite of 77, 92 

Rocky River, 

Diabase near 93 

Diorite near 93 

Syenite near 93 

Rogers Branch, granite near 137 

Rogers, R. J., quarry, sandstone at 233 

Rolesville, granite near 36, 37 

Rowan County, 

Basic igneous rocks of 119-122 

Diabase dikes in 122 



PAGE 

Table of 184 

Diorite in 59, 119, 120 

Gabbro in 120-122 

Granite in 12, 61, 100-119 

Granite dikes in 181 

Pink granite in 101 

Porphyritic granite in 58 

Rocks in 100-122 

Rowan Granite Co.'s quarries, granite 

of, 108 

Russell, I. C, referred to 237, 238 

Salisbury, 

Dikes near 58 

Granite near 100-119 

Granite dikes near 181 

Pink granite near 101 

Porphyritic granite area.... 58, 118, 119 
Sandstone, 

Absorption tests of 236 

Cementing materials of 216 

Color of 2, 216, 219 

Crushing tests of . . 228, 236 

Diabase dikes, in 223, 239-243, 266 

Test of for road metal 266 

Dikes in 21, 223, 239-243 

Distribution of 8, 218 

Freezing tests of . .234-236 

Jointing in 237-243 

Localities of 

Anson County 219-222 

Carrington-Gonella quarry ... .227, 228 

Carthage 223-226 

Chapel Hill 231 

Chatham County 229, 230 

Crowley Creek 226 

Cumnock 229 

Deep River 226, 229 

Duke quarry 233 

Durham County 229, 232, 233 

Glendon 226 

Goulds Fork 221, 222 

Governors Creek 226 

Hammonds quarry 221 

Hope River 231 

I. Horton's quarry 222, 223 

Linehan quarry 219 

Killetts Creek 224 

McLendon's Creek 225, 226 

McNeill, A. H., farm 224 

Moore County 223-229 

Morrisville 231 

Orange County 230-231 

Parson's quarry 222 

Polk, W. A., quarry 220-222 

Rackle and Lawrence quarry. . 228, 229 

Rockingham County 234 

Rogers, R. I., quarry 233 

Sanford area 227-229, 234, 235 

Stokes County 234 

University quarry 231 

Wadesboro area 21, 219-223 



INDEX. 



281 



PAGE 

Wake County 231, 232 

Quarrying and Working 218 

Structure of 217 

Texture of 216 

Uses 218 

Varieties of 216 

Weathering of 217 

Schists of Buncombe County 164 

Schists, lenses of limestone in 207 

Schulenberger's Branch, porphyritic 

granite at 95 

Seaboard Air Line Railway's quarry... 49 
Segregations in 

Granite at Concord City quarry 96 

Granite at Mt. Airy 154 

Granite at Smith quarry 69 

Granite in Stone Mountain area 162 

Hornblende granite at Kirkpatrick 

opening 70 

Serpentine 

Color of 211, 212 

Distribution of 212 

Localities of 

Alexander 213 

Barton Creek 215 

Buncombe County 212, 213 

Cook Gap 215 

French Broad River 213, 214 

Ivy River . 215 

Little Pine Creek 214 

Madison County. 214 

Marshall 214 

Olivette Station 213 

Raleigh 215 

Reddies River 214 

Reems Creek 213 

Wake County 215 

Watauga County 215 

Weaverville 213 

Wilkes County 214 

Wilkesboro 214 

Yancey County 215 

Origin of 210 

Structure of 211 

Texture of 211 

Uses of 212 

Weathering of 211 

Shearing test of building stone 258 

Shell Rock (see Limestone). 

Sheep Cliff Mountain, granite of 170 

Shepard, C. U, referred to 71 

Sinkhole Creek, marble near 203 

Sink Place, granite at 125 

Slate of Carolina Igneous Belt 60 

Age of 60 

Origin of 6 

Slickensides in crystalline rocks of 

North Carolina 178 

Sloan mill place, granite from 77 

Smith quarry, hornblende granite at. . . . 69 
Snell opening, dikes in granite of 68 



PAGE 

Southport, limestone near 206 

Spring Hope, granite near 25 

Statesville, 

Granite near 90 

Mica-schists near 81, 91 

Porphyritic granite near 80 

Stewart Place, granite at 92 

Stone, 

Grain of 2 

for Macadam 262-266 

Rift of 2 

for Road building 262-266 

Stone Mountain granite area 161-163 

Strength of granites 11 

Strike of dikes of Wadesboro-Rocking- 

ham area 20, 21, 243 

Stripping in opening new quarries . 249, 250 
Structure of 

Calcareous rocks 189 

Granite 9 

Sandstones and quartzites 217 

Serpentines 211 

Steele's. Mill, 

Dike near 20 

Granite near 15 

Stokes County, 

Limestone in 209 

Sandstone in 234 

Summerfield granite area, 

Diabase dikes in 138 

Granite of 138-140 

Sunset Mountain, quarries on 167 

Surface features of North Carolina 3 

Surry County, granite in 12, 152-160 

Swain County, 

Granite of 167, 168 

Limestone in 192 

Marble in 200, 202 

Rocks of 167, 168 

Syenite 

Localities of 

Cabarrus County 59 

Concord 59, 93, 94 

Hot Springs 171 

Hot Springs Granite area 171 

Madison County 171 

Porphyry (see Granite Altamaha 

granite area) 149-150 

Weathering of 94 

Tar River, granite near 38, 25 

Taylorsville, gneiss near 160, 161 

Texture of 

Limestones 188 

Marble 188 

Pegmatite dikes 179, 180 

Sandstones and quartzites 216 

Serpentines 211 

Unakite of Hot Springs granite area. 172 

Teeders Place, granite at 92 

Thawing and freezing, effect of on sand- 
stone 234-236 



282 



INDEX. 



PAGE 

Thornasville, basic igneous rocks near 

126, 127 

Toe Cane, marble near 204 

Toisnot (see Elm City). 

Toxaway Lake, granite near 171 

Toxaway Mountain 170 

Toxaway River, limestone near 208 

Transylvania County, limestone in 208 

Transylvania, Jackson and Macon coun- 
ties, 

Granite of 170, 171 

Rocks of . . . 170, 171 

Trap Hill, granite near 162 

Trap rock (see Diabase, Diorite, Gabbro 
and Greenstone). 

Trap rock, definition of 10, 11 

Trend of diabase dikes in triassic sand- 
stone of N. C 237, 243 

Trend of veins and dikes penetrating 
crystalline rocks of North Carolina, 

176, 184-187 

Trent River, limestone near 206 

Unakite of Hot Springs granite area, 

164, 172-174 

Color of 172 

Unakite of Madison County 164, 172-174 

U. S. Geological Survey, referred to.... 13 

University quarry, sandstone at 231 

Valley River, marble near, 30, 192, 197, 198 
Vance County, 

Granite in 12, 44, 52 

Granite dikes in 180 

Quarries in 30 

Van Hise, C. R., referred to 60 

Veins, aplite, in granite of Raleigh City 

quarry 180 

Veins and dikes, 

Acid ; 179-182 

Penetrating crystalline rocks of North 

Carolina 176-189 

Veins (pegmatite) in gneiss of Bun- 
combe County quarry 166 

Quartz in granite 181 

Veins in granite 

at Caldwell Place 70 

of Carolina Igneous Belt 58 

of Raleigh City quarry 32 

Walker Place, granite near 136, 137 

Wadesboro, granite near 14, 15 

Wadesboro Brownstone Co.'s quarry (see 
W. A. Polk's quarry), 

Diabase dikes near 238, 265 

Dikes in Triassic sandstones near. ... 21 

Sandstone near 219-223, 234 

Wadesboro-Rockingham granite area. .15, 20 
Wake County, 

Granites in 30 

Quarries in 30 

Sandstone in 231, 232 

Serpentine in 215 

Warren County, granite in 30, 42 



PAGE 

Warren Plains granite area 43 

Warren Plains, granite near 42 

Warrenton granite area, granite of 42 

Watauga County, 

Gneiss in 174 

Granite in 174 

Serpentine in 215 

Watson, Thomas L., referred to, 55, 60, 72, 

84, 129 
Weathering of 

Building stones 254-255, 268 

Effect of heat on . 254-255 

Effect of pyrite on 255 

Effect of rainfall on 255 

Relation of absorption to 259-260 

Relation of expansion and contrac- 
tion to . .258-259 

Calcareous rocks 189 

Dolomite 188-190 

Granite 10 

Marble 188-190 

Rocks of Carolina Igneous Belt 61 

Sandstone and quartzites 216 

Serpentines 211 

Weaverville, serpentine near 213 

Western Piedmont Gneiss and Granite 
Belt, 

Gneisses of 152, 160, 161 

Granites of 152-163 

Rocks of . . . 152-163 

Whiteside Mountain, granite of 170 

Wiggins Mill, granite near 21 

Wilhelm Place, granite at 90 

Wilkes County, 

Granites of 152 

Serpentine in 214 

Wilkes and Alleghany counties, 

Granites of 161-163 

Rocks of 161-163 

Wilkesboro, 

Granite near 161-163 

Serpentine near 214 

Williams, G. H., referred to 13, 60 

Williamsboro, granite near 53 

Wilmington, limestone near 205, 206 

Wilson County, granite in. 14, 21. 27 

Winston-Salem granite area 133-135 

Porphyritic granite of 133-135 

Winston-Salem 

Diabase dikes near 135, 136 

Tests of for road metal 265 

Gneiss near 135 

Porphyritic granite near 134 

Wise, granite near 44 

Woodfin quarry, limestone at 208 

Woodlawn, 

Limestone near 202, 209 

Marble near 202 

Woodleaf, 

Diorite near 59 

Granite near 100, 119 



Horth Carolina State Library 
Raleigh 



INDEX. 



283 



PAGE 

Woodleaf granite area 117 

Woodleaf Station, granite near .117 

Wolf Rock, granite of 162 

Woodroffe, Thomas, referred to 153 

Working and quarrying of granites.... 11 
Wyatt-Rolesville granite area, 



PAGE 

Dikes in granite of 38 

Granites of 36 

Wyatt Station, 

Granite near 36 

Pegmatite near 36 

Yadkin River, granite area 127, 128 



0d31 f 6!3l 



STATE LIBRARY OF NORTH CAROLINA 



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